Update stale links to `gmock_cook_book.md`.
I'm a new googletest user and found these links broken when reading the documentation.
PiperOrigin-RevId: 357786392
Fix some issues when running fuse_gmock_files.
The module path should be updated before importing `fuse_gtest_files`, since
the script may not run from the googletest repo root. We also need a non-frozen
set in order to track progress.
PiperOrigin-RevId: 337380466
