Use WizardNavigationButtons everywhere

[Arnei]

Some of our create modal were not consistently using the WizardNavigationButtons component. This patch changes that, thereby removing a bunch of duplicated code. All create modals should work the same as before.

[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-832

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-832

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/832/2024-09-05_07-37-31/ .
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.