misc: regenerate qml.qrc at configure time

Our qml.qrc is:
- commonly in conflict and prone to erroneous conflict resolution
- platform dependant (generation is used anyway for removing
  webengine dependant resources)
- a poorly maintained hodge-podge with resources in subdirectories
  that aren't grouped
- requires alteration when moving resources (if not done correctly,
  without tests, results in uncaught runtime failures)

This patch uses a python script at configure time to generate the
qml.qrc resource file, and removes it from versioning.

GitLab: #749
Change-Id: Ia2b81bb5b2c29d0bf6f5a5302e76795864e93e40