Turn DMF properties into DMFProperty types

[amylizzle]

winget stuff is more complicated than OD can handle right now, and it needs some type information needs to be passed along to process it properly. Notably pos and size vars can be accessed by their individual components, or formatted as json like {"x":123, "y":321}. Also pretty much all of the as blah features have different behaviour depending on the type of the var.

Requires: https://github.com/space-wizards/RobustToolbox/pull/5070

This PR implements:

• [x] Type information for DMF properties
• [x] Per-type serialization for each type of property
• [ ] Fully implements the as escaped/json/etc. winget commands (fixes #1730)
• [ ] Allows thing.pos.x winget access
• [x] Standardises TryGetProperty() and default values for descriptors