Rework setup buttons to fit in lower resolution displays

Qml controls

Add missing qml module

fix style in README

Fix the formatting at "Initialize submodules".

Controls respect QGCPalette settings. Also added test window.

Since this is generic Qml support not specific to FactSystem

Only seems to be missing in some cases but can’t hurt if already
installed.

Add Light/Dark theme support to QML

Back to non-modal, no pop-up Setup View

Removing unused selectedFilter argument from QGXFileDialog methods.

Remove erroneous use of QFileDialog::selectNameFilter()

Sync work branch.

Fix crash when no UAS

Fixes Issue #1162

Changing the order of the QGCFileDialog::getSaveFileName() function. The idea was to expand the existing QFileDialog version but as we removed the selectedFilter, we might as well make this more intuitive. The options argument is the one trully optional and should be last.
Adding an example to the documentation on how to go about figuring out what file type was returned by these functions.

Removed the “selectedFilter” argument from the QGCFileDialog functions along with references to it in unit tests.
Fixed function declarations and prototypes formatting while at it.
Changed the caption of a few file save dialogs with a more descriptive text (explicitly telling what is being saved).

Fixing bogus push of SettingsDialog.ui for merge hell

Remove erroneous use of QFileDialog::selectNameFilter(). No filters are to be selected. The argument selectedFilter is a pointer to a String to receive the filter selected/used by the user.

Main window central view and dock widget re-architecture

Will fix in next pull

- 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