blast: use frame instead of size and position

BufferStateLayers will have a source crop rect and destination
frame rect. The crop is the portion of the buffer that should be
displayed. The frame is where that portion of the buffer should
be displayed. The portion of the cropped buffer is scaled to fit
the frame.

Shader provided by romainguy@google.com.

Test: Transaction_test
Bug: 80477568

Change-Id: Ied3f3af2211132f79098aeb986292ee705a62219