Resolves: #7341
Previously, the Create Repository button was only enabled if a user was able to create a repo in their own namespace. However, if they had reached the global repo limit, but were stlll able to create a repo in an org, the button would still be disabled.
In this pull request, the create repo form now:
1. Behaves like it always did previously if the user has not reached the repo limit.
2. If the User has reached the repo limit, and they are unable to create a repo in any of their orgs (or they have no orgs), the create repo form is displayed as:

3. If the User has reached the repo limit, and the **limit is greater than zero**, an alert appears at the top of the form, and they are only allowed to choose from the orgs that they are allowed to create repos in:

4. If the User has reached the repo limit, and the **limit is equal to zero**, no alert is displayed, as no user can create repos on that instance, and they are only allowed to choose from the orgs that they are allowed to create repos in:

Co-authored-by: 0ko <0ko@noreply.codeberg.org>
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/7402
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Co-authored-by: Ryan Lerch <rlerch@redhat.com>
Co-committed-by: Ryan Lerch <rlerch@redhat.com>
- separate template
- ensure correct labelling of elements
- drop additional required indicators for field that already have
browser semantics (the icon has colour contrast issues anyway),
especially as the first dropdown cannot be left empty