Update and refactor the wasmi_wasi crate

[Robbepop]

With this PR the wasmi_wasi crate now clearly mirrors the wasmtime_wasi crate API.

[paritytech-cicd-pr]

BENCHMARKS

	NATIVE			WASMTIME
BENCHMARK	MASTER	PR	DIFF	MASTER	PR	DIFF	WASMTIME OVERHEAD
execute/ bare_call_0	1.49ms	1.51ms	🔴 1.76%	1.38ms	1.32ms	🔴 -4.06%	🟢 -13%
execute/ bare_call_0/typed	1.14ms	1.12ms	🟢 -2.13%	945.79µs	958.59µs	🔴 1.28%	🟢 -14%
execute/ bare_call_1	1.57ms	1.57ms	🔴 0.26%	1.44ms	1.41ms	🟢 -1.84%	🟢 -10%
execute/ bare_call_16	2.47ms	2.49ms	🔴 0.56%	3.35ms	3.34ms	⚪ -0.54%	🟢 34%
execute/ bare_call_16/typed	1.77ms	1.82ms	🔴 2.90%	1.60ms	1.60ms	⚪ -0.05%	🟢 -12%
execute/ bare_call_1/typed	1.21ms	1.23ms	🔴 1.65%	1.24ms	1.23ms	⚪ -0.11%	🟢 0%
execute/ bare_call_4	1.76ms	1.73ms	🟢 -0.82%	1.80ms	1.80ms	🔴 -0.04%	🟢 4%
execute/ bare_call_4/typed	1.33ms	1.27ms	🟢 -3.70%	1.21ms	1.24ms	🔴 2.70%	🟢 -3%
execute/ br_table	1.37ms	1.29ms	🟢 -5.63%	1.47ms	1.47ms	⚪ -0.13%	🟢 14%
execute/ count_until	707.70µs	633.46µs	🟢 -10.61%	1.01ms	1.01ms	⚪ 0.04%	🟡 59%
execute/ factorial_iterative	370.72µs	334.36µs	🟢 -9.74%	450.65µs	450.76µs	⚪ 0.14%	🟢 35%
execute/ factorial_recursive	605.70µs	591.80µs	🟢 -2.14%	862.93µs	837.27µs	🟢 -3.21%	🟢 41%
execute/ fibonacci_iter	1.47ms	1.47ms	⚪ 0.06%	2.06ms	2.06ms	⚪ -0.03%	🟢 41%
execute/ fibonacci_rec	5.02ms	4.90ms	🟢 -2.53%	7.51ms	7.25ms	🟢 -3.45%	🟢 48%
execute/ fibonacci_tail	1.17ms	1.23ms	🔴 5.37%	1.56ms	1.57ms	⚪ -0.02%	🟢 27%
execute/ global_bump	803.06µs	828.57µs	🔴 3.28%	1.36ms	1.35ms	⚪ -0.83%	🟡 63%
execute/ global_const	807.94µs	712.84µs	🟢 -11.83%	1.17ms	1.17ms	⚪ 0.01%	🟡 64%
execute/ host_calls	35.94µs	36.08µs	⚪ 0.45%	50.09µs	51.65µs	🔴 3.01%	🟢 43%
execute/ memory_fill	1.21ms	1.21ms	⚪ 0.03%	1.79ms	1.77ms	🟢 -1.36%	🟢 46%
execute/ memory_sum	1.32ms	1.19ms	🟢 -10.15%	1.80ms	1.79ms	⚪ -0.08%	🟡 51%
execute/ memory_vec_add	2.38ms	2.38ms	⚪ 0.01%	3.85ms	3.85ms	⚪ -0.04%	🟡 62%
execute/ recursive_is_even	1.04ms	1.04ms	⚪ -0.44%	1.62ms	1.69ms	🔴 4.08%	🟡 63%
execute/ recursive_ok	122.09µs	127.89µs	🔴 4.68%	190.23µs	195.18µs	🔴 2.72%	🟡 53%
execute/ recursive_scan	157.40µs	169.12µs	🔴 7.33%	246.46µs	242.66µs	⚪ -1.45%	🟢 43%
execute/ recursive_trap	12.51µs	12.54µs	⚪ 0.09%	20.64µs	20.73µs	⚪ 0.33%	🟡 65%
execute/ regex_redux	503.10µs	498.53µs	⚪ -0.89%	809.83µs	812.60µs	⚪ 0.38%	🟡 63%
execute/ rev_complement	457.25µs	459.70µs	⚪ 0.53%	720.42µs	718.03µs	⚪ -0.33%	🟡 56%
execute/ tiny_keccak	325.34µs	327.55µs	⚪ 0.65%	548.10µs	549.24µs	⚪ 0.19%	🟡 68%
execute/ trunc_f2i	781.42µs	775.34µs	⚪ -0.91%	1.47ms	1.46ms	⚪ 0.09%	🟡 89%
instantiate/ wasm_kernel	52.20µs	56.04µs	🔴 4.74%	57.19µs	57.19µs	⚪ -1.77%	🟢 2%
translate/ erc1155	234.10µs	235.03µs	⚪ 0.41%	454.40µs	445.74µs	🟢 -1.95%	🟡 90%
translate/ erc20	113.82µs	114.44µs	⚪ 0.58%	218.91µs	214.83µs	🟢 -1.71%	🟡 88%
translate/ erc721	160.04µs	163.04µs	🔴 1.73%	320.79µs	312.86µs	🟢 -2.22%	🟡 92%
translate/ spidermonkey	0.00ns	0.00ns	⚪ 0.80%	0.00ns	0.00ns	⚪ -1.32%	🟢 0%
translate/ wasm_kernel	4.04ms	4.07ms	⚪ 0.37%	8.20ms	8.08ms	🟢 -1.53%	🟡 99%

Link to pipeline