Mac compat

[cparish312]

Allows for basic Mac compatibility through:

1. Reorganizing the background object to prevent serializing complex objects into the process_images workers (by initializing the objects within the run function)
2. Commenting out print("QUEUE SIZE", self.images_queue.qsize()) as multiprocessing queue.qsize() is not implemented for Mac
3. When on Mac utils.get_active_window() always returns None. I couldn't find a simple Mac python replacement. The best lead involved calling AppleScript through subprocess

Mac config:
Chip: Apple M3 Max
macOS: 14.1.1

[apirrone]

Thanks for your contribution !

As soon as I can get my hands on a Mac, I will test and review.

Can you include your Mac's config in the PR text ? (CPU and OS version mainly)

[hunnywar]

@cparish312 @apirrone

I found 3 ways here to get name and title(if available)

1. using apple script
   (I tested it works)
   https://github.com/ActivityWatch/aw-watcher-window/blob/master/aw_watcher_window/macos_applescript.py

2. using jxa
   https://github.com/ActivityWatch/aw-watcher-window/blob/master/aw_watcher_window/macos_jxa.py

3. swift code
   https://github.com/ActivityWatch/aw-watcher-window/blob/master/aw_watcher_window/macos.swift