- Central widget no longer stacked. Views are added/removed to layout
to switch view
- Dock Widgets are globals with single instance of each type
- Both central views and dock widgets are just-in-time created saving
lots of memory

UAS may be around at constructor time

No need to force them to show

This way the dock doesn’t end up too wide

Don't use native widget siblings

Adding Issue #1157 to put back

QQuickWidget can’t handle this

Move ui style from MainWindow to QGCApplication

Moving more things off of MainWindow

Moving methods from MainWindow to QGCApplication so that more things
can run without a window. Helpful for testing.

Setup work

Emitting signal beforehand can lead to subtle bugs where code expects
value to be updated and it is not.

Summary buttons in Qml

Safety component

Fix intermittent UT failure