Fix(react-leaflet): Add interaction events to layer (#14085)

The `LeafletInteractionEvents` typing was missing from `LayerProps` , which caused issues with eg. `FeatureGroup`.

See details here
(http://leafletjs.com/reference-1.0.0.html#layer)

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react-leaflet/index.d.ts

@@ -95,7 +95,7 @@ declare const Pane: React.ComponentClass<PaneProps>;
 
 
 //There is no Layer class, these are the base props for all layers on the map
-interface LayerProps {
+interface LayerProps extends LeafletInteractionEvents {
     onadd?: (event: Leaflet.Event) => void;
     onremove?: (event: Leaflet.Event) => void;
 
@@ -109,7 +109,7 @@ interface LayerProps {
 }
 
 
-interface MarkerProps extends LayerProps, LeafletInteractionEvents, LeafletDraggingEvents {
+interface MarkerProps extends LayerProps, LeafletDraggingEvents {
     position: Leaflet.LatLngExpression;
     draggable?: boolean;
     icon?: Leaflet.Icon;