Profile management with wallpapers

Hello! I've implemented a few improvements and a new feature regarding profile management. - Profiles: users can now create and alternate between different profiles (with associated display settings). As you can see, my branch originates from Flexksx's work on profiles (https://github.com/Flexksx/nwg-displays/tree/persistant-profiles), which was not completed. So I was able to fix the detected bugs on that branches and implemented some additional features. - Profile-bound wallpapers: * Added a "Profile-bound wallpapers" checkbox to the main UI. Users can now toggle whether wallpapers should be saved and loaded alongside display profiles. * Updated settings_applier.py and main.py to respect this setting. * Added corresponding default configuration in tools.py and localization strings in en_US.json. - Dialog sizing: * Modified the profile creation and selection dialogs in profiles.py to be non-resizable (set_resizable(False)). * Adjusted margins slightly so these dialogs occupy only the necessary space, making them look cleaner. My features are working pretty fine on my machine, but some more testing might be required (specially on Sway, since I use Hyprland and didn't test the Sway compatibility stuff that I coded). Thank you for your work on nwg-displays!