Use underscores to prevent trailing dot in folder names

[christianlupus]

Topic and Scope

Closes #2332

Concerns/issues

There could be name clashes if the first 97 chars of two recipes are equal.

Formal requirements

There are some formal requirements that should be satisfied. Please mark those by checking the corresponding box.

• I did check that the app can still be opened and does not throw any browser logs
• I created tests for newly added PHP code (check this if no PHP changes were made)
• I updated the OpenAPI specs and added an entry to the API changelog (check if API was not modified)
• I notified the matrix channel if I introduced an API change

[github-actions]

Test Results

   12 files    584 suites   1m 33s ⏱️
  573 tests   573 ✅ 0 💤 0 ❌
2 292 runs  2 291 ✅ 1 💤 0 ❌

Results for commit 533005f.

[christianlupus]

In case there are already some recipes with the trailing dot, the user has to open the recipe and just store it again. That will move it to the correct location without a trailing dot.

[christianlupus]

/approve

[nextcloud-cookbook-bot]

Automatically approved by GitHub action on behalf of /approve