Capture Method Interface

[Avasam]

I'd like to abstract all capture methods behind an interface. This will allow the main logic to be independent of any method's quirks or platform/OS dependency. The interface and all capture methods will go in their own module.

The interface needs to expose:

• A function to initialize the capture method (some methods need to hook/create/initialize resources).
• A function to get the current frame. If frame is not ready it should return the previous frame, with an indication as such (so far only the only method that will implement this is device capture. It'll act the same way as WGC API)
• A function to close the capture method (some methods need to release resources).
• A function to try and recover the captured window (happens if the captured window was closed, then re-opened)
• A property is_available to keep platform-specific checks in the capture-method module.