tests: add codeset-utf8 as a feature #3

Job	Run time
linux-mingw, AM gcc	3m 26s
msvc, CM x64-windows schannel MultiSSL U	39m 35s
linux-mingw, CM gcc	1m 21s
msvc, CM x64-windows openssl	9m 22s
msvc, CM x64-uwp openssl	2m 31s
old-mingw, CM 9.5.0-x86_64 schannel	8m 22s
msvc, CM x64-windows libressl	8m 21s
old-mingw, CM 7.3.0-x86_64 schannel U	11m 52s
msys2, AM x86_64 !proxy	8m 50s
msvc, CM x64-windows boringssl-ECH	47m 28s
old-mingw, CM 6.4.0-i686 schannel !unity	3m 34s
msvc, CM x64-windows wolfssl	8m 56s
msys2, AM x86_64 default	9m 10s
msys2, CM x86_64 default	2m 8s
msvc, CM x64-windows gnutls	35m 24s
msys2, AM x86_64 default R	8m 5s
mingw, AM x86_64 default	6m 39s
msvc, CM x64-windows msh3	11m 0s
mingw, AM x86_64 c-ares U	11m 25s
mingw, CM x86_64 schannel c-ares U	6m 26s
mingw, CM ucrt-x86_64 schannel R TrackMemory	2m 48s
mingw, CM clang-x86_64 openssl	2m 7s
mingw, CM x86_64 schannel R uwp	2m 40s
mingw, CM i686 schannel R	2m 26s
	4h 13m 56s

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