Fixes#8639.
For your convenience this PR is made via AGit for you to see the issue directly in Codeberg ^^
### Tests
- I added test coverage for Go changes...
- [ ] in their respective `*_test.go` for unit tests.
- [x] in the `tests/integration` directory if it involves interactions with a live Forgejo server.
I am not sure how to best write a unit test for this. It looks like there isn't any AGit PR in the default test database. The integration test in `test/integration/pull_review_test.go` creates one by manually running Git commands. I could just copy all that code to do the same in another test, but I feel bad about duplicating this. Can they be sensibly migrated to some helpers module that can be reused across tests? Or can we add an AGit PR to the test database? Or can we modify the `Flow` attribute of a PR in a test just for the sake of simulating that it's an AGit one?
### 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
- [x] I do not want this change to show in the release notes.
- [ ] 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.
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/8642
Reviewed-by: Gusted <gusted@noreply.codeberg.org>
Co-authored-by: Antonin Delpeuch <antonin@delpeuch.eu>
Co-committed-by: Antonin Delpeuch <antonin@delpeuch.eu>
This implements the UI controls and information displays necessary to allow reviewing pull requests by stepping through commits individually.
Notable changes:
- Within the PR page, commit links now stay in the PR context by navigating to `{owner}/{repo}/pulls/{id}/commits/{sha}`
- When showing a single commit in the "Files changed" tab, the commit header containing commit message and metadata is displayed
- I dropped the existing buttons, since they make less sense to me in the PR context
- The SHA links to the separate, dedicated commit view
- "Previous"/"Next" buttons have been added to that header to allow stepping through commits
- Reviews can be submitted in "single commit" view
Talking points:
- The "Showing only changes from" banner made sense when that view was limited (e.g. review submit was disabled). Now that it's on par with the "all commits" view, and visually distinct due to the commit header, this banner could potentially be dropped.
Closes: #5670#5126#5671#2281#8084

## Checklist
The [contributor guide](https://forgejo.org/docs/next/contributor/) contains information that will be helpful to first time contributors. There also are a few [conditions for merging Pull Requests in Forgejo repositories](https://codeberg.org/forgejo/governance/src/branch/main/PullRequestsAgreement.md). You are also welcome to join the [Forgejo development chatroom](https://matrix.to/#/#forgejo-development:matrix.org).
### 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.
Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/7155
Reviewed-by: Earl Warren <earl-warren@noreply.codeberg.org>
Reviewed-by: Beowulf <beowulf@beocode.eu>
Co-authored-by: Lucas Schwiderski <lucas@lschwiderski.de>
Co-committed-by: Lucas Schwiderski <lucas@lschwiderski.de>