EndPointsOverlay: Replace `MapMarkerIcon` into `fromMarkerIcon` and `toMarkerIcon`

[binh-dam-ibigroup]

I think the way the <EndpointsOverlay> tag reads is inconsistent in the sense that
it defines two distinct fromLocation and toLocation, so you would imagine there is a separate icon prop for the from and to locations. In reality, the component defines a single MapMarkerIcon that represents two separate icons (or more, if the location prop is used). My suggestion would be to split MapMarkerIcon into a fromMarkerIcon and a separate toMarkerIcon. For each of these icons, the implementer can have separate logic to draw different icons based on location for instance.