Support for Certificate Transparency primitives and verification

[loosebazooka]

I'm curious if BC (specifically java for me) would be interested in supporting the primitives and verifiers for certificate transparency (CT). I think this ties to the existing x509 certificate support. (Context: https://certificate.transparency.dev/howctworks/)

It would include (but potentially not limited to):

1. Creating CT primitives (Logs, signed certificate timestamps (SCTs), etc)
2. Verification of Certificates' log entries.

This is all done offline, logs do not necessarily need to be contacted to verify inclusion if provided keys are trusted. BC would remain un-opinionated on log providers and simply provide what is necessary to verify cryptographic validity.

I can write out a longer design proposal if it makes sense. (cc: @patflynn)