Example inventory cleanup 🧽

[captainbarbosa]

Addresses https://github.com/mapbox/ios-sdk-examples/issues/343 by removing the following examples:

Example	Proposed changes
AnnotationViewsAndImagesExample	❌ We should remove this because we want to discourage using MGLAnnotationImages in favor of symbol layers
BuildingsExample	❌ Remove in favor of BuildingLightExample
ImageAnnotationExample	❌ Remove in favor of symbol-layer based examples
PointHotspotExample	❌ Remove in favor of ClusteringExample
SatelliteStyleExample	❌ Remove in favor of SwitchStyles example.
SelectFeatureExample	❌ Remove in favor of FeatureSelection example.
CustomAnnotationModelExample	❌ Remove in favor of AnnotationViewExample example.