Enable COSE Sign1 authentication for governance endpoints

[achamayou]

Second half of #3875, with tests:

• POST /gov/ack
• POST /gov/proposals
• POST /gov/proposals/{proposal_id}/ballots
• POST /gov/proposals/{proposal_id}/withdraw

The change to clients.py to use COSE Sign1 is a bit of a bodge, but gets us a fair bit of coverage quickly. I will continue to clean up the implementation and the tests, but I think the interface is good to go for rc0.

[ghost]

cose_authn_gov@52327 aka 20221026.33 vs main ewma over 20 builds from 51805 to 52321

Click to see table

main

build_id	build_number	tpcc_sgx_cft^	tpcc_sgx_cft_mem	ls_sgx_cft^	ls_sgx_cft_mem	ls_jwt_sgx_cft^	ls_jwt_sgx_cft_mem	tpcc_virtual_cft^	tpcc_virtual_cft_mem	ls_js_sgx_cft^	ls_js_sgx_cft_mem	ls_virtual_cft^	ls_virtual_cft_mem	ls_jwt_virtual_cft^	ls_jwt_virtual_cft_mem	ls_full_js_sgx_cft^	ls_full_js_sgx_cft_mem	ls_js_virtual_cft^	ls_js_virtual_cft_mem	ls_full_js_virtual_cft^	ls_full_js_virtual_cft_mem	ls_js_jwt_sgx_cft^	ls_js_jwt_sgx_cft_mem	ls_js_jwt_virtual_cft^	ls_js_jwt_virtual_cft_mem	hist_sgx_cft^	RB put (/s)^	CHAMP put (/s)^	RB get (/s)^	CHAMP get (/s)^
51805	20221021.2	5750.81	8.3497e+07	17709.5	1.71746e+07	6168.59	1.56017e+07	11181.3	0	2345.54	9.57242e+06	42683.3	0	10188.4	0	1996.68	9.57242e+06	4351.77	0	3461.51	0	1921.35	9.04813e+06	3212.55	0	26940	902870	1.3806e+06	9.27948e+06	3.58669e+07
51813	20221021.5	5793.12	8.3497e+07	17799.1	1.6126e+07	6120.3	1.56017e+07	11336.7	0	2348.47	9.57242e+06	40642.5	0	11519.1	0	2044.46	9.31027e+06	4260.82	0	3425.09	0	1910.74	9.04813e+06	3223.42	0	28834.2	907679	1.37643e+06	9.22103e+06	3.59298e+07
51826	20221021.9	5621.67	8.24484e+07	17870.6	1.6126e+07	6151.43	1.56017e+07	10567.1	0	2357.11	9.57242e+06	42390.5	0	10341.2	0	1980.47	9.31027e+06	4289.94	0	3385.16	0	1926.41	9.04813e+06	3174.02	0	26911.8	885814	1.34551e+06	9.13063e+06	3.53713e+07
51832	20221021.11	5611.78	8.3497e+07	17968.1	1.63882e+07	6067.88	1.56017e+07	10984.6	0	2340.66	9.57242e+06	43765.1	0	10141	0	1975.36	9.57242e+06	4366.3	0	3463.29	0	1877.25	9.04813e+06	3228.09	0	24824.9	891090	1.36788e+06	9.21273e+06	3.56174e+07
51844	20221021.15	5666.7	8.42835e+07	17806.4	1.63882e+07	6079.43	1.56017e+07	10939.3	0	2310.1	9.57242e+06	42325.1	0	10632.1	0	2004.41	9.31027e+06	4249.92	0	3457.66	0	1914.02	9.31027e+06	3218.37	0	23210.3	908278	1.37283e+06	9.22099e+06	3.57411e+07
51922	20221023.1	5780.97	8.21863e+07	17755.2	1.6126e+07	6062.06	1.53396e+07	11341.2	0	2339.54	9.57242e+06	42755.5	0	10599.5	0	1976.51	9.57242e+06	4421.86	0	3478.67	0	1923.12	9.04813e+06	3215.35	0	24171.6	908401	1.36688e+06	9.14686e+06	3.57417e+07
51929	20221024.2	5649.55	8.32349e+07	18197.1	1.66503e+07	6173.25	1.58639e+07	11020	0	2353.95	9.31027e+06	42507.8	0	10714.4	0	1956.4	1.14074e+07	4234.49	0	3585.69	0	1881.83	9.04813e+06	3241.89	0	21619.3	924057	1.38349e+06	9.30901e+06	3.57411e+07
51934	20221024.4	5696.81	8.37592e+07	17882.1	1.6126e+07	6157.47	1.58639e+07	11228.6	0	2348.42	9.31027e+06	43074.1	0	10611.6	0	1978.09	1.27181e+07	4309.36	0	3534.43	0	1930.14	9.31027e+06	3202.17	0	28527.6	905468	1.35252e+06	9.41601e+06	3.56794e+07
51943	20221024.8	5747.57	8.37592e+07	17784.2	1.63882e+07	6134.12	1.56017e+07	11138.8	0	2359.15	9.83456e+06	41682.8	0	10100.2	0	1984.33	9.83456e+06	4213.87	0	3372.76	0	1930.04	9.31027e+06	3197.46	0	24870.3	898869	1.37809e+06	9.39876e+06	3.58669e+07
51959	20221024.15	5782.18	8.45456e+07	17690.6	1.6126e+07	6032.81	1.56017e+07	11371.8	0	2359.2	9.57242e+06	42816.8	0	10018.8	0	1980.58	9.57242e+06	4301.09	0	3541.08	0	1914.75	9.04813e+06	3206.07	0	24628.2	920195	1.36952e+06	9.33446e+06	3.58669e+07
52014	20221024.40	5712.19	8.37592e+07	17593.8	1.63882e+07	6139.58	1.58639e+07	11398.6	0	2447.74	9.83456e+06	43113.2	0	10654.3	0	1979.58	9.31027e+06	4225.14	0	3426.22	0	1921.92	9.04813e+06	3251.09	0	27874.6	906348	1.37366e+06	9.33025e+06	3.57417e+07
52041	20221024.53	5760.17	8.55942e+07	17977.4	1.58639e+07	6168.98	1.53396e+07	11321.6	0	2360.75	9.57242e+06	43611.8	0	10138.7	0	1990.82	9.57242e+06	4255.73	0	3463.17	0	1937.17	9.31027e+06	3202.65	0	25100.1	902277	1.37044e+06	9.22099e+06	3.57417e+07
52054	20221024.58	5681.71	8.29727e+07	17484.3	1.6126e+07	6021.95	1.56017e+07	11044.1	0	2351.04	9.57242e+06	41604.5	0	10104.2	0	2011.09	1.14074e+07	4372.67	0	3532.07	0	1915.13	9.04813e+06	3171.67	0	27719.6	885654	1.36824e+06	9.40308e+06	3.58669e+07
52062	20221025.1	5619.86	8.29727e+07	17763.6	1.6126e+07	6027.95	1.56017e+07	10867.9	0	2351.98	9.31027e+06	43201.8	0	10139.3	0	1976.69	9.31027e+06	4325.6	0	3455.55	0	1924.45	9.04813e+06	3413.03	0	28088.8	908070	1.35376e+06	9.20019e+06	3.47702e+07
52148	20221025.38	5718.6	8.29727e+07	17753.4	1.6126e+07	6044.86	1.58639e+07	11063.7	0	2358.53	9.57242e+06	40818	0	10463.8	0	1979.66	9.57242e+06	4339.26	0	3383.05	0	1921.17	9.04813e+06	3229.84	0	28238.2	888304	1.37246e+06	9.46824e+06	3.58036e+07
52163	20221025.43	5600.9	8.32349e+07	17696.9	1.66503e+07	6085.06	1.56017e+07	11038.1	0	2358.74	9.83456e+06	41761.6	0	10179	0	1983.17	9.57242e+06	4350.36	0	3469.75	0	1889.35	9.31027e+06	3335.97	0	28399.5	903435	1.38201e+06	9.39881e+06	3.62478e+07
52174	20221025.47	5689.44	8.32349e+07	17535.4	1.63882e+07	6022.79	1.58639e+07	11133.2	0	2412.92	9.57242e+06	43517.8	0	10340.2	0	1918.01	9.83456e+06	4330.74	0	3411.3	0	1919.16	9.31027e+06	3218.81	0	27570.9	914116	1.40687e+06	9.30901e+06	3.61831e+07
52195	20221026.2	5681.17	8.3497e+07	17589.3	1.66503e+07	6028.17	1.53396e+07	11554.9	0	2370.68	9.57242e+06	41858.6	0	10139.1	0	1984.11	9.57242e+06	4270.16	0	3340.51	0	1963.27	9.04813e+06	3053.82	0	27354.3	903111	1.34426e+06	9.21269e+06	3.58042e+07
52214	20221026.8	5602.67	8.27106e+07	17410.9	1.6126e+07	6036.44	1.53396e+07	11377	0	2364.04	9.57242e+06	43249	0	10217.2	0	1979.57	9.31027e+06	4275.83	0	3312.68	0	1879.58	9.04813e+06	3029.65	0	23651.4	884697	1.3768e+06	9.30055e+06	3.57411e+07
52321	20221026.31	5580.3	8.27106e+07	15985.1	1.63882e+07	5350.9	1.50774e+07	10453	0	2045.31	8.78598e+06	38970.4	0	10294.1	0	1683.25	8.78598e+06	4251.76	0	3285.73	0	1609.17	7.99955e+06	3177.25	0	27773.5	832968	1.18137e+06	8.17226e+06	3.08369e+07

cose_authn_gov

build_id	build_number	tpcc_sgx_cft^	tpcc_sgx_cft_mem	ls_sgx_cft^	ls_sgx_cft_mem	ls_jwt_sgx_cft^	ls_jwt_sgx_cft_mem	ls_js_sgx_cft^	ls_js_sgx_cft_mem	ls_full_js_sgx_cft^	ls_full_js_sgx_cft_mem	ls_js_jwt_sgx_cft^	ls_js_jwt_sgx_cft_mem	tpcc_virtual_cft^	tpcc_virtual_cft_mem	hist_sgx_cft^	ls_virtual_cft^	ls_virtual_cft_mem	RB put (/s)^	CHAMP put (/s)^	RB get (/s)^	CHAMP get (/s)^	ls_jwt_virtual_cft^	ls_jwt_virtual_cft_mem	ls_js_virtual_cft^	ls_js_virtual_cft_mem	ls_full_js_virtual_cft^	ls_full_js_virtual_cft_mem	ls_js_jwt_virtual_cft^	ls_js_jwt_virtual_cft_mem
52191	20221025.53	5665.85	8.3497e+07	17415.1	1.71746e+07	6101.99	1.56017e+07	2359.3	9.57242e+06	1980.65	9.31027e+06	1915.09	9.57242e+06	10827.9	0	24461	41003.3	0	898321	1.3744e+06	9.21688e+06	3.54939e+07	10082.1	0	4044.97	0	3417.56	0	3463.31	0
52290	20221026.22	5656.06	8.40213e+07	17362.3	1.66503e+07	6101.72	1.56017e+07	2362.16	9.57242e+06	1984.16	9.31027e+06	1965.78	9.31027e+06	11223.8	0	17023.3	41856	0	890192	1.35843e+06	9.25846e+06	3.5249e+07	10607.3	0	4307.26	0	3371.08	0	3301.42	0
52320	20221026.30	5672.1	8.40213e+07	17594	1.66503e+07	6011.78	1.56017e+07	2351.24	9.31027e+06	1992.67	9.31027e+06	1922.05	9.04813e+06	10943.2	0	28856.7	39785.4	0	904913	1.4037e+06	9.44649e+06	3.58042e+07	10512.5	0	4310.29	0	3430.98	0	3292.57	0
52325	20221026.32	5590.63	8.29727e+07	16324.9	1.6126e+07	5449.4	1.53396e+07	2070.59	9.31027e+06	1692.13	8.52384e+06	1627.65	7.99955e+06	10846.2	0	27286.7	39742.5	0	829326	1.16484e+06	8.17333e+06	3.0718e+07	10479	0	4274.43	0	3459.12	0	3305.48	0
52327	20221026.33	5504.39	8.27106e+07	15993.4	1.63882e+07	5392.79	1.53396e+07	2080.28	9.04813e+06	1678.77	9.04813e+06	1591.39	7.99955e+06	11014.2	0	24488.5	40773.2	0	816909	1.18324e+06	8.15011e+06	3.08476e+07	9833.54	0	4159.64	0	3426.93	0	3256.02	0