Add/Use new DropPanel control

[DonLakeFlyer]

Problems:

• When clicking in map to execute a position oriented command you lose context of where exactly you clicked when the command popup shows
• In the Plan view the hamburger item uses a QGCMenu which is based on QMl Menu control. A while back Qt screwed up this control such that it doesn't support dynamic visibility of items like it used to. This in turn made it very wonky looking. You can see it here:

Solution was to create a new DropPanel control which is based on the the ToolStrip drop panel control. This popup has an arrow indicator which points to the place the items are referring and doesn't suffer the problems QGCMenu has. I've switched over the Map click popup to use that as well as the Plan view hamburger drop down.

Here you can see a map click pop at the extreme edge of the map. Normally the control will drop to the right of the click. But if there is lack of room it will switch to drop to the left of the click.