feat: display TLS certificate checks configuration in connectivity view

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Screenshot:

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We should also warn about plaintext configurations because if plaintext connection is used then strict TLS certificate checks do not help. Have not decided where to put it yet, should probably be a red item at the top of "Incoming Messages" and "Outgoing Messages" if IMAP or SMTP configuration using plaintext connection is detected.

I also thought about adding proxy information to connectivity view, but this better goes to another screen where user can also change the settings: https://github.com/deltachat/deltachat-android/issues/3276

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Closing as it is not finished and to avoid interfering with https://github.com/chatmail/core/issues/7269

I also think if we revive this, it should not show anything when certificate checks are enabled. Instead, show "Warnings" section telling what is wrong (no TLS, TLS checks disabled etc.) and do not show this section at all by default.