Add logging for TypeErrors in plugin settings

[ademuri]

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What does this PR do and why is it necessary?

This PR logs TypeErrors which occur inside of on_settings_save for plugins. I'm working on developing a plugin, and had a bug in my plugin which caused a TypeError in my override of this function. The log message incorrectly stated that I was calling octoprint.plugin.SettingsPlugin.on_settings_save incorrectly. This also changes that error message to indicate that calling that function incorrectly may be the cause.

How was it tested? How can it be tested by the reviewer?

I ran this with a plugin which generates a TypeError in the on_settings_save function. I also ran the unit tests.

What are the relevant tickets if any?

You can see that someone else was misled by this issue here: https://community.octoprint.org/t/solved-i-need-some-help-with-my-plugin/15732/13

[github-actions]

Automatic PR Validation failed

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• The PR's target branch master is not among the allowed target branches: maintenance, devel, staging/maintenance, staging/devel. Please only create PRs against these.

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[GitIssueBot]

This pull request has been mentioned on OctoPrint Community Forum. There might be relevant details there:

https://community.octoprint.org/t/solved-i-need-some-help-with-my-plugin/15732/14

[cp2004]

Kept meaning to sort this one out, but forgot several times... Thank you, should result in less confused plugin authors 👍