Close (sub)project warning message

[galethil]

Checklist

• [x] I have followed (at least) the PR section of the contributing guide.
• [x] I fixed all necessary PR warnings
• [x] The commit history is clean
• [x] The E2E tests are passing
• [x] If possible, the issue has been divided into more subtasks
• [x] I did a self review before requesting a review from another team member

Description

How to test

1. Create new project and subproject
2. Close subproject
3. Close project
4. In both cases you should see the warning in all languages

Closes #1871

[github-actions[bot]]

	Warnings
:warning:	No CHANGELOG added.
:warning:	There were changes in the frontend, but no E2E-test was added or modified!

Generated by :no_entry_sign: dangerJS against 4d66e90eb9fc7043f351c785059a8185a8d033e0

[openkfwCI]

	Notes	Time
:white_check_mark:	Note for Reviewer: E2E tests on pipeline 59520 on remote server succeeded	Mon, 17 Jun 2024 12:21:10 +0000

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