Handling of plugin errors

[fheft]

If a plugin crashes (e.g. open-coffee/opencoffee-frontpage-plugin-feed#7) the whole frontpage crashes with a 'Whitelabel Error Page'.

Plugin errors should not affect the remainder of the frontpage.

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.