Added a delete dataset action to dashboard

[hotzenklotz]

Every now and again there appear old, unimported datasets on your dashboard, mostly on WK instance with file system access. Thus far there is no easy way to delete them. This PR adds a "Delete" action to these unimported datasets.

I had to refactor the dataset action view into a React function component in order to use the query hooks. Unfortunately, Git does not track the changes very well.

URL of deployed dev instance (used for testing):

• https://___.webknossos.xyz

Steps to test:

1. Duplicate any DS in your binaryData folder and remove datasource-porps.json to make it go kaputt
2. Re-scan datasets on your dashboard
3. See and press "Delete" action
4. Profit

Issues:

• None

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(Please delete unneeded items, merge only when none are left open)

• Updated changelog
• Updated migration guide if applicable
• Updated documentation if applicable
• Adapted wk-libs python client if relevant API parts change
• Removed dev-only changes like prints and application.conf edits
• Considered common edge cases
• Needs datastore update after deployment

[hotzenklotz]

Blocked by #7429

[philippotto]

nice, works well 👍