Change text for "time in queue"

[Arnei]

Originally #1396

"Time in queue" is one of the variables shown for worklow operation details. However, the name is misleading, as this does not refer to the time the operation (or the job representing it) was waiting before starting. Instead, it represents the time all the jobs the operation has spawned were waiting.
Which is why "time in queue" so often has the value "0ms", as many workflow operations simply don't spawn an jobs.

This patch attempts to make this more clear by changing "time in queue" to "total subjobs time in queue". Suggestions are welcome.

[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/admin-interface:pr-1563

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/admin-interface:pr-1563

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/1563/2026-04-07_07-26-11/ .
It might take a few minutes for it to become available.