Instead of converting to a string immediately, only convert to a string
when necessary, like for trace logging. This reduces the size of the
`USDPrimReader` base class by 24 bytes, makes several Vectors and Maps
smaller at runtime, and reduces some unnecessary string allocations and
conversions in various other places.
The recently added python Hook `get_prim_path` dictionary will now
contain `SdfPath` objects rather than strings; removing the string
conversion cost when calling other USD APIs like `GetPrimAtPath` which
take in `SdfPath` objects to begin with.
This also makes the code a bit more self explanatory since the type
makes it clear what kind of path you are dealing with.
Pull Request: https://projects.blender.org/blender/blender/pulls/133954
6c11811710