Revert "CORE-5597 Updated irods-avu-migrator to import only."

This reverts commit 1d8fdf6328c9da05e98eb1d25cbeebe6da96fa39.

Conflicts:
	tools/irods-avu-migrator/src/irods_avu_migrator/templates.clj
CORE-5597 Updated irods-avu-migrator cmd options.

Split the metadata AVU imports and the ICAT AVU deletes and updates into separate commands, executed by different command-line options.