Add Bounds Padding

[levitatejay]

Currently it isn't easy to automatically offset the map/markers (for when you have a control that sits over the map)

Google have updated their API to handle this but it isn't supported in this library yet: https://developers.google.com/maps/documentation/javascript/reference/map#Map.fitBounds
https://stackoverflow.com/a/53565456

Here are old issues about adding the feature: #716 #1471

And here is a pull request that implemented it but was never released: #1478

[DaSchTour]

Just released it to NPM https://www.npmjs.com/package/@ng-maps/core