Make the plugin a CType

[oliverklee]

I as a user want to move the plugin to the proper CType level.

Acceptance criteria

• the plugin is moved to the CType level
• the plugin works as before

Additional Information

Like this:
https://review.typo3.org/c/Packages/TYPO3.CMS/+/82665
We don't need an upgrade wizard as this plugin is not used in production sites.

Also like this:
derhansen/sf_event_mgt@0f1d7a3

[cumuru]

The database dump in https://github.com/oliverklee/TYPO3-testing-distribution will need an update once this will be merged.