Send attribution Id to native SDK

[aednlaxer]

First draft of attributionId call:

• Call method to send attribution Ids (Android, iOS but not web)
• Use version_check.yaml and a set of new tools to check if package's version matches the version in the native layer (java (Android), .h (iOS), .dart (web))
• Had to bump min iOS version from 14.0 to 15.0 in order to use a newer GoogleMaps pod that has attribution Id function available

[jokerttu]

Example app is not right place to do this. We need to do this somehow on the package code.
As devs can easily left this out.
Maybe we need to do this on first map view initialization (if not done yet)?
Or if it is possible to detect that key is given for GMSServices somehow.
Let's ask Caio / and their team what they think of that.
This means that applications do not report the package usage, unless map is shown on the app. (which sounds right?)

[jokerttu]

Could it be done here:
https://github.com/CodemateLtd/packages/blob/main/packages/google_maps_flutter/google_maps_flutter_ios/ios/Classes/FLTGoogleMapsPlugin.m#L12

Please check if this is called always after AppDelegate is completed; I suppose it is, but let's be sure. Then we can be sure the provideApiKey is always called before running the code.

[aednlaxer]

I changed the code to use selector for this call but it seems to be called in this order:

1. FLTGoogleMapPlugin
2. AppDelegate

Is there a problem with this? The reference doesn't say it should be called after map API key is set

[aednlaxer]

Will create a new clean PR