Remove SSLv3

[vavroch2010]

[nhorman]

At a minimum doing this involves removing any code guarded by the macro OPENSSL_NO_SSL3. That currently amounts to about 15 code locations.

It will also involve the removing of the requisite configuration option to enable sslv3, fixing up the tests which attempt to test sslv3 such that they no longer do so, and removing command line options which allow the run-time enablement of this feature (which are not guarded by the OPENSSL_NO_SSL3 macro)

There will likely be some additional fallout, requiring the removal of dead code which stems from the code removal above, but we won't know exactly what that is until we do it all.

[t8m]

There is already a PR by @kroeckx openssl/openssl#28044

[vavroch2010]

Consider adding openssl/openssl#6165