jami-daemon: add OCSP verification, store & trust

• ☑ revoke jams device

  https://review.jami.net/c/ring-daemon/+/12742

• ☑ openssl OCSP server setup

  https://github.com/binarytrails/notes/blob/master/software/ssl.md#setup-server

• ☑ proof-of-concept with opendht http library

  https://github.com/binarytrails/various/blob/master/cpp/gnutls/ocsp.cpp

  • ☑ generating / sending OCSP request

  • ☑ receiving / processing OCSP request

• Jami-daemon integration: https://review.jami.net/c/ring-daemon/+/12792

  • ☑ Verify certificate with OCSP if present with a TLS session wrapper

  • ☑ Test/Debug/Validate JAMS for OCSP feature

  • ☑ Save OCSP responses into Certificate Store

    ocsp/
    └── <Certificate UID>
        └── <OCSP Response Serial Number>

  • ☑ Load OCSP responses into Certificate Store

  • ☑ OpenDHT: Use OCSP requests store/trust implementation in Crypto

  • ☑ IM: Validate peers with OCSP responses prior to communication

    https://github.com/savoirfairelinux/opendht/pull/464

  • Implement OCSP periodic request sending/caching (IM are not automatic)

    (ensures no revoked user can send messages even if the tls wrapper is not called as in sip calls)