Add pkgbases export endpoint to developer reports

[benmezger]

This PR adds pkgbases export endpoint to developer reports, mirroring the existing todolist endpoint.

This solves #659.

[jelly]

Since svn_root is meaningless in our new Git packaging repository workflow lets not depend on it for new code and instead make the endpoint /pkgbases without the svn_root. We can later refactor the To-Do list view to link to pkgbases instead of community or packages.

[benmezger]

Since svn_root is meaningless in our new Git packaging repository workflow lets not depend on it for new code and instead make the endpoint /pkgbases without the svn_root. We can later refactor the To-Do list view to link to pkgbases instead of community or packages.

@jelly that makes sense. With regards to the HTML changes, that was done to keep the same visual functionality as the todo page, but since we will drop svn from the endpoint, that makes sense.

I've updated the code accordingly.

[jelly]

This still needs some UI to make the link discover-able I would copy the design of the existing ToDo list but just make it Link to pkgbases

[jelly]

If you are up to it, would be nice to put this in a separate function and commit and refactor the existing report function to use that so we aren't copying logic around.