[Feature] Add macos support

[dkbast]

From my understanding, contacts is available on mac (and various other apple OSes) - I believe it would be great if we could also support macos - I suspect that this should be possible using the shared implementations "darwin" flag, that would require a minimum version of Flutter 3.7, so might be a "major" version increment for fast_contacts, or copy pasting the code into macos? I tried getting darwin to work, but the mix of "todays" Flutter and the ios implementation was too much for a quick 15 minute tinkering session.

If you can point me in the right direction I would love to assist :)

https://developer.apple.com/documentation/contacts

[s0nerik]

This should be quite easy. I'll look into it when I have some spare time. Increasing the minimum flutter version for a next plug-in version should not be a problem as well.

[dkbast]

I actually managed to get it to work on a mac only spike - two might be issues: permission handler does not support mac yet (PR seems to be open), so I had to bale that in and there are different imports for mac and ios needed - not sure how to solve that yet - but should be doable.
Will push my proof of concept soonish

[dkbast]

@s0nerik - this is my "working poc" for a mac implementation - only minor changes, mostly copy paste from ios:
https://github.com/dkbast/fast_contacts_mac

An implementation without its own permission handling would depend on Baseflow/flutter-permission-handler#1207 to land