testSpaceContainer: Deduplicate Utils.update_gui()
testSpaceContainer: Deduplicate Utils.update_gui()

There was an identical function in tests/utils.js, so use that one and
remove the duplicate.

https://phabricator.endlessm.com/T17220

endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib,endlessm/eos-knowledge-lib