OPENPGP PLUGIN: Don't list expired/revoked GPG keys

[eerielili]

Hello,
@fiaxh This PR should close #91

I also changed the text when no key is selected from "No keys available. Generate one" to "No keys available. Generate one or check if your key isn't expired or revoked!"

I created a gpg key expiring few minutes after generation with a timestamp of 20240412T105500:

Here's a screenshot 2 minutes before expiring:

After closing dino and opening it back after the key expired:

But the input text box can still be used to send message, which are marked as failed but no reason is given.
I'll see if it's possible to block input on a revoked or expired key, and also have it checked without opening and closing dino.

Kind regards,
lili

[eerielili]

Update: I did find a way. I'll need to modify the encryption_activated method in encryption_list_entry.vala. Working on it.

Edit: bingo!

Edit 2: I splitted the message, so if it's revoked:

or expired:

It still doesn't trigger if the key expires or revokes while dino is in use, but switching the encryption methods back and forth to GPG do rerun the check for expiry / revocation status and block the field accordingly.

Edit 3: It does trigger by switching back and forth conversations, or clicking the conversation in the left pane.

[eerielili]

I did add a warning in the account panel if the current selected key has expired or is revoked:

[eerielili]

It still doesn't trigger if the key expires or revokes while dino is in use

I finally managed to do that without needing to click on left pane or switching back and forth conversations.
It involves calling method on_encryption_activated in send_text() method in main/src/ui/chat_input/chat_input_controller.vala if PGP is the encryption method, triggering the checks in the plugin.

Now, if you try to send a message but the key has expired or has been revoked while Dino is in use and you're in a chat, the input should be blocked with the following depending on your situation:

With this, I think all bases are covered.

@NicoHood @cjj20 Feel free to test and give feedback anytime