Reduce duplicate code in action cells

[Arnei]

Mostly by turning the button that's copy-pasted everywhere into its own component.

These are the "action cells":

How to test this

Can be tested as usual, no configuration or Opencast patch necessary. There should be no functional changes, so the main thing to test here is that everything behaves as usual.

[github-actions]

Use docker or podman to test this pull request locally.

Run test server using develop.opencast.org as backend:

podman run --rm -it -p 127.0.0.1:3000:3000 ghcr.io/opencast/opencast-admin-interface:pr-1018

Specify a different backend like stable.opencast.org:

podman run --rm -it -p 127.0.0.1:3000:3000 -e PROXY_TARGET=https://stable.opencast.org ghcr.io/opencast/opencast-admin-interface:pr-1018

It may take a few seconds for the interface to spin up.
It will then be available at http://127.0.0.1:3000.
For more options you can pass on to the proxy, take a look at the README.md.

[github-actions]

This pull request is deployed at test.admin-interface.opencast.org/1018/2025-01-31_15-15-29/ .
It might take a few minutes for it to become available.

[github-actions]

This pull request has conflicts ☹
Please resolve those so we can review the pull request.
Thanks.

[github-actions]

This pull request has conflicts ☹
Please resolve those so we can review the pull request.
Thanks.

[owi92]

lgtm, everything's still working.