v3.0.0

• ⚠️ Removed clusterZoom argument from getLeaves, getChildren and getClusterExpansionZoom methods — it's now encoded into cluster_id numbers, so there's no longer a need to track it separately.
• ⚠️ As a result of the change above, the same data will have different cluster_id numbers compared to previous releases.
• Fixed getLeaves to properly handle features with null properties.
• Improved handling of null geometries (supercluster will ignore them instead of throwing an error).
• Imrpoved error reporting — specifying invalid cluster_id will now result in a descriptive error.