Now saving last window frame on layout. Using to restore original size from unmaximize

[jtaala]

This PR fixes an issue affecting some windows when using the new maxmize within tiling functionality by @valpackett.

Some application window weren't restoring to the size before the maximize-horizontally signal was received (e.g. code, brave weren't being restored for me).

This PR implements saving the last window size frame on layout call, which can then used to in unmaximizing a window before calling toggleMaximizeHorizontally.

[jtaala]

Hey @valpackett, could you please test these changes?

These changes fix an issues that affects some application windows.

Let me know if you run into any issues. I've disabled the layout call in the signal since layout will be called when the window is max'd / resized (from the resize handler). However, if doing another layout call afterwards helps with some some of those issues you mentioned in #870 please let me know (I couldn't reproduce any of them).

Thanks.