🎪 Change the way platforms are imported ⚠️ DO NOT MERGE ⚠️

[stojanovic]

Goal: update the structure so we can import new platforms without adding them to the core and add plugin support.

To do:

• [x] Update structure and allow users to pass an instance of the platform class in platforms list
• [x] Automatically export items defined in platform class constructor
• [x] Export platform classes
• [ ] Review
• [ ] Trigger postDeploy method in post deploy
• [ ] Add more tests
• [ ] Beta test each platform