Implement reverse sorting of groups

[claremacrae]

Background

The way that group by effectively works:

• each group is created and contains a list of tasks
• the tasks in each group are sorted according the sort by options
• the groups are then written out in alphabetical order

(The implementation is in a different order, but that describes the observable behaviour...)

This causes confusion if group by and sort by .... reverse are using the same field.

Example

For example:

This query

```tasks
done
sort by done reverse
group by done
```

Can give this result - note the dates of the group names are ascending:

Proposal

I always intended to make reverse-grouping possible:

```tasks
done
sort by done reverse
group by done reverse
```

In the above, the sort becomes redundant as the grouping would be reversed anyway.

Implementation details

Currently there is no link between the Sort code and the Group code. I wasn't able to figure out a way sort the groups in anything other than alphabetical order.

Some refactoring behind the scenes, continuing the work I am doing for #664, will make this easier to implement. I cannot promise any time scales yet though.

[claremacrae]

I think this is what #747 was probably referring to.

[BlackRedLight]

This will be wonderful

[hauntedhost]

Would love this!

[claremacrae]

For those who don't already know...

Please, no more +1s or reminders on this (or other tickets). They are just a distraction and interruption.

If you would like to express support for ideas, up-vote them. That's what raises their profile when prioritising time to spend on the project.

[claremacrae]

I know the +1s are well-intentioned.

[claremacrae]

Also reported in #1347

[claremacrae]

I'm delighted to announce that reverse sorting of groups has just been released on Tasks 3.7.0.
Docs are at: https://publish.obsidian.md/tasks/Queries/Grouping#Reversing+groups

[Silv-1]

Can this be used on group by function x

[claremacrae]

Yes: https://publish.obsidian.md/tasks/Scripting/Custom+Grouping#Expressions

[claremacrae]

group by function reverse x