fix: Trim tags on adding or editing

[Koc]

Summary

It is possible create multiple tags with leading/trailing slashes: bar, bar, bar , etc. This confuses users and causes usage of wrong tags. Let's trim input.

Checklist

• Code is properly formatted
• Sign-off message is added to all commits
• Tests (unit, integration, api and/or acceptance) are included
• Screenshots before/after for front-end changes
• Documentation (manuals or wiki) has been updated or is not required
• Backports requested where applicable (ex: critical bugfixes)

[Koc]

Failed tests looks unrelated

[github-actions]

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[susnux]

In general ok, but I am not a fan of the backend doing other things than I did on the fronend.
So maybe we should already show this / handle this correctly on the fronend.

[Koc]

@susnux but solution on BE side will work for any api client

[susnux]

but solution on BE side will work for any api client

Yes so it should be done here but would be great to see it also in the frontend

[Koc]

/backport to stable30