Remove templates for setting/getting style properties
Remove templates for setting/getting style properties

Summary:
@public

Replaces the `StyleProp` template with a simple setter macro / inlined getter code.

The template was introduced to replace more extensive macros that would generate function signatures, too.
Here, we keep the spirit of that change by only generating function bodies.

Reviewed By: SidharthGuglani

Differential Revision: D13439612

fbshipit-source-id: 36f6a86917d035be6891cb736d1f288d8e02f5cf

facebook/litho,facebook/litho,facebook/litho,facebook/litho,facebook/litho,facebook/litho