Sort the incoming Alembic objects by name before processing them. This
mirrors what is already done in USD to partially side-step Blender's
quadratic behavior when checking object names.
The file contained in issue #118839 contains over 365000 individual
objects. This change allows loading to be ~4x faster; from 2.2 hours
down to 28 minutes.
Additionally, change the progress bar to report in finer-grained steps
to better indicate that progress is still being made.
Pull Request: https://projects.blender.org/blender/blender/pulls/118869
2353fd8f91