fix(machines): Allow deselection of machines in a selected group MAASENG-3720

[ndv99]

Done

• Selecting a group of machines:
  • adds the system IDs of (visible) machines in that group to the selection state, instead of the group key
  • does NOT select every machine in that group, only the ones on screen
• Machines in a selected group can now be unselected

QA steps

I recommend doing this using a MAAS instance with a good amount of sample data.

• Go to machine list
• Select a group of machines
• Ensure the checkboxes are all checked in that group, but not disabled
• Ensure you can unselect machines
• Select a group of machines that's bigger than what can be shown on one page ("Ready" is good in sampledata)
• Ensure only the machines on that page are selected

Fixes

Resolves MAASENG-3720
Resolves LP:2056157

Screenshots

Before

After

[webteam-app]

Demo

Jenkins

demos.haus

[tmerten]

QA:
In a partially selected group, the select button of the group stops working

Code:
I think you forgot updating the tests, see inline comment.

[tmerten]

lgtm! Thanks for adding that partial select test.