Display current trust status for encrypted messages
The purpose of this PR is to enable dynamic trust display of encrypted messages (i.e. be able to indicate the current trust level, not necessarily the one that was set while receiving the message. The sketch of the WIP change:
- ChatControl uses the new API to get all known keys for a JID (contact JID or MUC JID) and passes it to the ConversationTextView
- ConversationTextView uses the fpr trust information (from 1) and the AdditionalData (which it uses currently) to calculate trust for known fingerprints
- If a fingerprint has been added, current trust is used as a fallback until the window is reloaded.
- If fingerprint trust has been changed, the changes not visible until the window is reloaded
See the related gajim-plugins PR at gajim-plugins!130