Add change username endpoint

[edenhaus]

Breaking change

Proposed change

Add change username ws endpoint and code in auth module.
New username need to be normalized otherwise an error will be raised

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• This PR fixes or closes issue: fixes #
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[github-actions]

There hasn't been any activity on this pull request recently. This pull request has been automatically marked as stale because of that and will be closed if no further activity occurs within 7 days.
If you are the author of this PR, please leave a comment if you want to keep it open. Also, please rebase your PR onto the latest dev branch to ensure that it's up to date with the latest changes.
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[github-actions]

There hasn't been any activity on this pull request recently. This pull request has been automatically marked as stale because of that and will be closed if no further activity occurs within 7 days.
If you are the author of this PR, please leave a comment if you want to keep it open. Also, please rebase your PR onto the latest dev branch to ensure that it's up to date with the latest changes.
Thank you for your contribution!

[frenck]

Small improvement comment, otherwise ✅

../Frenck

[frenck]

Thanks, @edenhaus 👍

../Frenck