Permit librarians to move editions to a new work

[Freso]

Closes #9235

fix

Technical

Adds a new page-local variable is_librarian which is then checked for in the call that decides whether to add the “-- Move to a new work” option in the Work move dropdown list.

Testing

NOTE: I have not run tests or manually tested this in a working environment, as I haven’t set one up (yet?), and the pre-commit hook failed due to an Error getting the version from source vcs which seems unrelated to this PR.

1. Edit an edition with a librarian account which is neither super librarian nor admin.
2. The “-- Move to new work” option should be available.

I didn’t find anywhere where the existing behaviour was tested in automated tests, and thus also haven’t edited or added any such tests.

Screenshot

Stakeholders

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