Add `set_cert_verify_callback` (`SSL_CTX_set_cert_verify`) #941

Job	Run time
clippy	3m 32s
rustfmt	10s
Test (stable)	2m 6s
Test (arm-android)	2m 11s
Test FIPS integration	2m 56s
Test (arm64-android)	2m 16s
Test (i686-android)	2m 1s
Test (x86_64-android)	2m 1s
Cross build from macOS to Linux (x86_64-unknown-linux-gnu)	2m 2s
Test (aarch64-ios)	2m 21s
Test (aarch64-ios-sim)	2m 59s
Cross build from macOS to Linux (FIPS) (x86_64-unknown-linux-gnu)	3m 38s
Test (x86_64-ios)	3m 11s
Test features	7m 36s
Test (i686-linux)	2m 16s
Test (arm-linux)	2m 19s
Test (aarch64-linux)	2m 23s
Test (arm64-macos)	3m 41s
Test (x86_64-macos)	2m 28s
Test (x86_64-mingw)	6m 40s
Test (i686-msvc)	6m 45s
Test (x86_64-msvc)	5m 9s
	1h 10m 41s

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