feat!: Rework resize operations with resize mode

[mmstick]

Pressing Super + R will now enter a resize mode, which has a visual indicator to show whether the resizes will grow or shrink the window. Arrow keys and hjkl will grow the window in the four directions by default. Holding Shift will invert the arrows and allow shrinking the window from the four sides.

[jacobgkau]

A couple of problems on 1083bdd:

• The Super-Enter shortcut still works to enter window management mode, but doesn't allow resizing windows anymore; with no visual indication, this is going to be confusing to current users upgrading.
• With two windows split horizontally on a 1080p display, I can can only make a window larger without holding shift, and I can only make a window smaller while holding shift; the arrow indicators seem to indicate that I should be able to use the left or right arrow key in either mode (with the only difference being inverted while holding shift.)
  • Upon reading your description again, I understand the reason this isn't working is because I can't grow a window against the edge of a display; perhaps the on-screen arrow indicators should only be present for directions where resizing is possible, or else maybe the control scheme could use further consideration.

Separately from these issues, a change like this is going to need @pop-os/ux input/approval.

[jacobgkau]

For reference, here is what the indicator currently looks like for resizing, without and with the shift key:

I noticed a couple of other issues while getting those pictures:

• The Print Screen key does not work while the resize mode is open. (It works in the current window management mode.)
• Clicking anywhere on the screen while the resize mode is active does nothing; current window management mode does not exit on click (perhaps it should), but it doesn't entirely block the mouse like this.
• Because of the background color chosen for the resize indicator, there's a lack of contrast with Terminal (and probably other apps using Pop colors):
  

[jacobgkau]

The new arrow placement is easier to understand:

simplescreenrecorder-2022-08-10_09.49.47.mp4

It does seem strange that I need to e.g. use Shift in order to be able to use two of the arrow keys, and release Shift to be able to use the other two, in the above example. It makes me wonder why I need shift at all. Of course, the reason is that sometimes a window has three or more resizeable edges:

simplescreenrecorder-2022-08-10_09.51.26.mp4

But still feels a little strange.

These points still stand:

• The Super-Enter shortcut still works to enter window management mode, but doesn't allow resizing windows anymore; with no visual indication, this is going to be confusing to current users upgrading.
• The Print Screen key does not work while the resize mode is open. (It works in the current window management mode.)

[mmstick]

Waiting for new designs from UX for these issues