ceph_objectstore_tool: Fixes to make import work again

The is_pg() call is now true even for pgs pending removal, fix broken
    finish_remove_pgs() by removing is_pg() check.
Need to add create_collection() to the initial transaction on import

Fixes: #10090

Signed-off-by: David Zafman <dzafman@redhat.com>
Reviewed-by: Sage Weil <sage@redhat.com>