- Relative links were not properly being rendered, because the links
were being made absolute against the repository URL instead of
repository URL + /src/branch, which leads to incorrect links.
- Restore the 'old' behaviour. When there's branch information, that
should be used as base for links.
- Adjusts the test cases.
- Regression of 637451a45e
- Resolves https://codeberg.org/Codeberg/Community/issues/1411
(cherry picked from commit 0e9d52e291)