Move SKP version extraction into JS

two reasons:
1. It prevents any crash during reading from prevening a version number being returned from wasm.
2. It lets me use a common solution for reading a version number from SKP files and MSKP files.

bug:skia:10832

Change-Id: Icad27690aac9d614d72140ea4b88b350faf21a4f
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/334897
Reviewed-by: Derek Sollenberger <djsollen@google.com>
Commit-Queue: Nathaniel Nifong <nifong@google.com>
1 file changed