VCL: rename TryDrawPolyLineDirectNoAA to TryDrawPolyLineDirectNoAACheck

Change-Id: I7355db3294f5aaa3b4f4bac802ba064724ad2214
VCL: Renamed two functions

Renamed functions:

+ supportsOperation -> SupportsOperation
    For consistency

+ DrawAlphaBitmap -> DrawDeviceAlphaBitmap
    I want to make it more clear that these are the functions that call
    on mpGraphics to actually draw on the graphics device

Change-Id: Ic4951bfcc0ac0c09fe5b6908dfdf1f699a634265