Server-side validation for whitespace in title

[samin-z]

• Target version: main

Summary

on Server-side it is possible to add whitespace for title.

TODO

Add extra validation for title to check it's not empty or whitespace.

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Documentation (manuals or wiki) has been updated or is not required

[samin-z]

/backport! to stable1.0

[backportbot]

The backport to stable1.0 failed. Please do this backport manually.

# Switch to the target branch and update it
git checkout stable1.0
git pull origin stable1.0

# Create the new backport branch
git checkout -b backport/7759/stable1.0

# Cherry pick the change from the commit sha1 of the change against the default branch
# This might cause conflicts, resolve them
git cherry-pick e1ab13ce 79bcfaac

# Push the cherry pick commit to the remote repository and open a pull request
git push origin backport/7759/stable1.0

Error: Failed to check for changes with origin/stable1.0: No changes found in backport branch

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Learn more about backports at https://docs.nextcloud.com/server/stable/go.php?to=developer-backports.