Promote Search SDK as a replacement of Geocoder

[friendoye]

Search SDK for Android now is the recommended way to access Geocoding API on Android platform.
To promote Search SDK usage this PR:

1. Adds Geocoder deprecation note;
2. Assigns services-geocoding ownership to @mapbox/search-sdk-android team

[LukasPaczos]

Since we are recommending the switch, should we also deprecate the classes in this project and point to the Search SDK?

[friendoye]

@LukasPaczos I wouldn't mind adding deprecation notes and annotation to Geocoder's classes, but I'm not fully convinced it's necessary:

1. Search SDK is available only for Android platform, while Java SDK's artifacts are available for JVM as well. Customers using Geocoder on JVM will not be able to migrate to Search SDK, making deprecation notes a bit misleading;
2. Search SDK doesn't have plans to support batch geocoding right now, but Geocoder provides such functionality (migration guide emphasises this fact). Thus we can only deprecate a few methods of MapboxGeocoding class.

[LukasPaczos]

Thanks, that makes total sense 👍