Tweaks to toolbar visibility

VIsual tweaks

Added configurable value grid to toolbar

Re-architect toolbar for better customization capabilities. Also use less real estate.

More work on encapsulation in Fly View

Programmatic switch to SetupView leaves two buttons selected

Prevent view switching apis support a stack

View switch prevention support

Change to use combo

Restructure toolbar to make it Flickable

Use showIndicator property to set correct visibility in loader. This leads to correct spacing on all platforms.

Change to combobox

Fix spacing

Use QGCCombBox with alternateText for better understanding of the ability to click on these indicators

Update all files that use a QML Menu item to QtQuick.Controls 2.4 to solve the issue of a menu showing up in random places on Android.

Handles branding logo visibility according to available space.

Restore QGC to its normal UI layout (buttons on toolbar)