Compose GeoViewProxy lacks GeoView ports

dev4567

Compose MapViewProxy lacks a bunch of APIs already accessible from the underlying MapView / GeoView e.g.: 

getCurrentViewpoint

layerViewStateChanged

etc.

Please, add those proxy getters to the MapViewProxy so we could experience the same level of integrity in the Compose world.

PuneetPrakash

the `currentViewPoint` and the `layerViewState` values are available as callbacks from the Composable MapView, 

onViewpointChangedForCenterAndScale: ((Viewpoint) -> Unit)? = null,
onViewpointChangedForBoundingGeometry: ((Viewpoint) -> Unit)? = null,

...
onLayerViewStateChanged: ((GeoView.GeoViewLayerViewStateChanged) -> Unit)? = null,

https://github.com/Esri/arcgis-maps-sdk-kotlin-toolkit/blob/main/toolkit/geoview-compose/src/main/java/com/arcgismaps/toolkit/geoviewcompose/MapView.kt#L132

https://github.com/Esri/arcgis-maps-sdk-kotlin-toolkit/blob/main/toolkit/geoview-compose/src/main/java/com/arcgismaps/toolkit/geoviewcompose/MapView.kt#L157

These callbacks are invoked everytime a new value for the viewpoint or layerViewState is available and provide you the latest value. 

We do have a method on the `GeoViewProxy` that you can use to find out the LayerViewState for a given layer at this time. 
https://github.com/Esri/arcgis-maps-sdk-kotlin-toolkit/blob/main/toolkit/geoview-compose/src/main/java/com/arcgismaps/toolkit/geoviewcompose/GeoViewProxy.kt#L305