feat: add static location and live location support
Description of the changes, What, Why and How?
This PR adds
LiveLocationManager class - helper to handle registered live locations (see use in React SDK PR)
Channel.sendStaticLocation - sends a message with single static_location attachment
Channel.startLiveLocationSharing - sends a message with single live_location attachment and dispatches local live_location_sharing.started event to notify LiveLocationManager instances
Channel.stopLiveLocationSharing - dispatches local live_location_sharing.stopped event to notify LiveLocationManager instances (should probably just update message attachment with stopped_sharing instead)