Resolve #23848
This PR put an edit file button on pull request files to allow a quick
edit for a file. After the edit finished, it will return back to the
viewed file position on pull request files tab.
It also use a branch view file link instead of commit link when it's a
non-commit pull request files view.
<img width="1532" alt="image"
src="https://github.com/go-gitea/gitea/assets/81045/3637ca4c-89d5-4621-847b-79702a44f617">
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Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: silverwind <me@silverwind.io>
538790ad1d