This patch addresses bug #102594.
These changes enhance the prim_path_mask USD import
option to allow masking on multiple paths.
- Changed the prim_path_mask import property to
a string of arbitrary size.
- Multiple paths may be specified in a list delimited
by spaces, commas or semicolons.
- Now using the pxr::UsdStagePopulationMask class to apply
the masking when opening the stage, which is more efficient
and which preserves the full prim paths.