**Backport:** https://codeberg.org/forgejo/forgejo/pulls/9914
## Checklist
This PR contains both #9889 and #9912, since it depends on the one, and the other provides a test for it.
The exact reasoning behind its logic is described here: https://codeberg.org/forgejo/forgejo/issues/9473#issuecomment-7976186
This PR should return the behaviour back to how it was before a PR to Gitea changed it.
Only the resulting Database-Entry will reference the line blamed commit, now also with the correct adjusted line.
While the context diff view is pulled from the commit the commenter actually commented on.
Resolvesforgejo/forgejo#9473
### Tests
- I added test coverage for Go changes...
- [ ] in their respective `*_test.go` for unit tests.
- [ ] in the `tests/integration` directory if it involves interactions with a live Forgejo server.
- I added test coverage for JavaScript changes...
- [ ] in `web_src/js/*.test.js` if it can be unit tested.
- [x] in `tests/e2e/*.test.e2e.js` if it requires interactions with a live Forgejo server (see also the [developer guide for JavaScript testing](https://codeberg.org/forgejo/forgejo/src/branch/forgejo/tests/e2e/README.md#end-to-end-tests)).
### Documentation
- [ ] I created a pull request [to the documentation](https://codeberg.org/forgejo/docs) to explain to Forgejo users how to use this change.
- [x] I did not document these changes and I do not expect someone else to do it.
### Release notes
- [ ] I do not want this change to show in the release notes.
- [x] I want the title to show in the release notes with a link to this pull request.
- [ ] I want the content of the `release-notes/<pull request number>.md` to be be used for the release notes instead of the title.
Co-authored-by: BtbN <btbn@btbn.de>
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/9920
Reviewed-by: Mathieu Fenniak <mfenniak@noreply.codeberg.org>
Co-authored-by: forgejo-backport-action <forgejo-backport-action@noreply.codeberg.org>
Co-committed-by: forgejo-backport-action <forgejo-backport-action@noreply.codeberg.org>
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