More work on encapsulation in Fly View

Fly View: Move business logic inside controls

Major rework to support terrain profile display and terrain collision reporting

Fix display of Continue Mission/Change Alt after Pause

Mavlink terrain protocol support

Put back ToolStrip titles which were mysteriously removed

added function to FlightView to show the checklist if switching views from a view other than FlightView and if checklist should be shown

Makes more sense for it to be in VideoStreamer as it takes care of managing
the video streams.

Fix sizing/scrolling

Use parsebin for automatic stream demuxing and parsing; Automatically insert rtpjitterbuffer for RTP streams to avoid video stuttering

Switch to decodebin and use decoder with highest rank; Use GL context provided by qmlglsink; Fix JNI code for AndroidMedia initialization

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

Fix video initialization - VideoReceiver did not start because sink was not created because videoBackgroundComponent was not loaded on startup if video was disabled