Gitea: Git tag support in the UI

[silverwind]

The UI is currently missing support for git tags. I propose the following additions:

• A page that lists all tags /user/repo/tags
• Handling of individual tag URLs /user/repo/tags/{tag}. They could either redirect to the tagged commit or present a individual page like GitHub does.
• If a commit is tagged, show it on the commit page and maybe on the commit list.
• Show a counter of tags in the repository statistics.

Related: https://github.com/go-gitea/gitea/issues/5693 (possible prereq?)

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs during the next 2 weeks. Thank you for your contributions.

[JLuc]

Also add an easy-to-use button to git tag