Add trusted key servers for matrix into config file, and begin cosmetic TUI additions

[jessebot]

This gets us ready for the following changes which have been pushed out recently:

• https://github.com/small-hack/matrix-chart/releases/tag/matrix-11.0.0
• https://github.com/small-hack/argocd-apps/commit/89c0038767767406caa3da428543787b59c1d5f3

If you want to federate your matrix server, you may also need to provide:

• trusted_key_servers

You can provide a list of maps like this for trusted_key_servers:

apps:
  matrix:
    init:
      values:
        - server_name: matrix.friend.com
          verify_keys:
            ed25519:auto: abcdefghijklmnopqrstuvwxyzabcdefghijklmopqr

[!Note]

The TUI changes for trusted_key_servers are cosmetic only for right now. You cannot change your matrix trusted server via the TUI yet. You can only change it via the config.yaml file.

Also closes #266 by upgrading textual to 0.70.0

[jessebot]

Further work on this will be done in #269