Add onMapReady event to GMap

[scalancea]

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Current behavior
When creating the GMap component, there is no way to access the internal map object instantaneously. You can sent the map object using a button to take it via template variable .getMap().

Expected behavior
It would be useful to have the map object available through an Output event emitter

What is the motivation / use case for changing the behavior?
There are cases though, when you need access to the map object as soon as possible (ideally, instantaneously), for example for setting the initial position of the map using map.fitBounds(bounds);