Make report groupings function as links

[#1]

The grouping header of a report should function as a link to that object, if applicable.

For example, if I'm running a task report and I'm grouping by project, I should be able to click on the name of the project from the grouping header and be taken to that project.

It's redundant to have to add a column for the project name just so that you can click the link and go to the project.

[#2]

I'd like to see it, though I suspect it may be complicated. We do have a similar need for this because of the way we need to run aggregate reports on projects via a Task report, for example.