Offline vehicle support

Includes ability to load params

This prevents problems with toolbox references from inside
QGCTool::setToolbox calls.

-GIT_TAG is redundant
-closes #4023

-we need a monotonically increasing integer for android versionCode and
this works better across multiple branches

Cancel polygon edit in appropriate places

Fix dialog buttons stuck in disabled state

Allow GenFenceManager to specify QML for fence editor

Remove unused code

Update README.md [ci skip]

PX4 fence plugin

Add altitde to survey item coordinate

Add video streaming dependency

libgstreamer-plugins-bad1.0 is not installed if 3rd party plugins are opted-out during OS install

Also change Plan Element selection ui

Camera survey enhancement with additional parameters

formating

More work on GeoFence support

- GeoFence support comes from plugin
- Circle fence support
- Better param support

Revert "Mavlink 2.0 support"

Adding static RTSP libraries and dependencies to Android.

Adding missing library to Linux build.

rearrange layout

camera model and sensor size closer together

Moving Video Settings to bottom of General Settings.

Fix inverted logic when disabling UVC.