Add ability to group by urgency

[claremacrae]

Question

Requested in reddit:

When querying is it possible to group tasks by the urgency level?

Current answer

Not yet. It will become easy when I've finished the work on #664:

refactor the Query class to be more modular

I had an initial implementation of grouping by urgency level, and the main problem was the sorting of the groups was meaningless, as the groups are displayed in alphabetical order, and current have no notion of sorting depending on the kind of data the group represents.

Here's an example screenshot showing the non-useful order of the groups in the right-hand-side:

[claremacrae]

This will be included in the next release.
Details in:

• feat: Add 'group by urgency' #1944

[claremacrae]

group by urgency was released in 3.6.0.

group by urgency reverse was released in 3.70.