Feature: The window stat isn't preserved between sessions

[YohDeadfall]

Cosmic-files version:

https://github.com/pop-os/cosmic-files/commits/774ccf955f59f24cf9493f9249d20788ad394d48

Issue/Bug description:

For me, the problem is that Files doesn't store the window state information or doesn't restore it between launches of the applications. It's quite crucial for small displays due to the file info panel that eats space and automatically appears when an entry is selected.

Steps to reproduce:

1. Start Files.
2. Maximize the window.
3. Close Files.
4. Start Files.

Expected behavior:

The window state should be successfully restored from the previous run.

Other notes: