qt: Disable Qt modules when support is unavailable

Change-Id: Icef6c460a46daeaef3c1d2d551c9c4bb1fe514ab
testing: Download baselines in a required library

The GUI isn't always built, so baselines may not get downloaded.

Change-Id: I45695cd80e45afd2fb7bd8230aaa1af1cbde93db
Merge topic 'use-external-data' into next

602440cc testing: Download baselines in a required library
884a57b2 qt: Disable Qt modules when support is unavailable