Function getSelectedFeatures

getSelectedFeatures(): JMapSelection
JMap.Map.Selection.getSelectedFeatures

Returns the current map selection as a javascript map (= a javascript object) where :
- the key is the layer element id
- the value is an array of feature (an empty array if layer doesn't have features selected)
Returns JMapSelection
Example
```
// returns the current selected features by layer id
JMap.Map.Selection.getSelectedFeatures()
```