Support KMLIcons

[CoryFoy]

Describe the bug
When displaying a KML Point, it shows a Yellow Pushpin always instead of the KML Icon

To Reproduce
Steps to reproduce the behavior:

1. Create a KML file with a point that has a custom marker
2. Import into TAK Aware

Expected behavior
The map shows the icon specified in the KML file

Additional context
There's a multi-step process to get the icon. It can be defined inside of the <Placemark> directly, but can also be referenced via a <Style> node which in turn might be referenced by a <StyleMap> node. Note also that icons might refer to URLs, or refer to files inside the KMZ (if it is a KMZ)