PTFM-10341 dx build prompts when making an app public the first time
Make "dx build" output less chatty

* Use logger instead of printing directly to stderr in a few places
* Raise minimum log level to WARNING for "dx build"
PTFM-10341 Test fixes for 109ffd7

* App ACL tests need to wait for next server-side update
* Previous commit changed the behavior of a "dx build" invocation used
  in test_update_app_authorized_users
PTFM-9548: dx --version reports to stdout instead of stderr
Bugfix: allow --class workflow in dx find data