Fix type error when opening statistics page

[ferishili]

This PR fixes #566
by properly async call (using dispatch!) to fetch the user info before fetching the statistics info!
This PR needs actual statistic data to make sure it works properly, but for the start the error is now gone, and the page should not be interrupted!

[github-actions]

Hi @ferishili
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[github-actions]

This pull request is deployed at test.admin-interface.opencast.org/568/2024-06-04_12-08-55/ .
It might take a few minutes for it to become available.

[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-568

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-568

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.

[ziegenberg]

This also fixes #282

Edit: I was wrong!

[ziegenberg]

Note: ICLA has been filed (see #546 (comment))

[github-actions]

This pull request is deployed at test.admin-interface.opencast.org/568/2024-06-04_12-29-51/ .
It might take a few minutes for it to become available.

[ferishili]

Keep in mind that I haven't tested this for #282 (which happens in events details level)
I found this bug simply by navigating to the statistics menu in left pane action bar!

[ziegenberg]

Does what it says on the tin