Subscriber as primary (#8)

* Update protos

* Signal client

* Improve transport

* First implementation

* Fix publish

* Update `PCTransport` for debounce negotiation

* debounce func

* reconnect & events

* Update debounce func

* engine events

* make sure events don't emit after dispose

* prefix flutter_webrtc

* Cleaner `iceServers` update

* don't mutate user provided params

* fix tests

* event manager

* Fix: `Room.onDisconnected` gets fired multiple times

* data publish in example

* cleaner logic

* safer events

* un-prefix with LK

* organize imports

* Clean up

* remove `Tuple`

* `EventsEmitter` can now be directly listened to

`EventsEmitter` extends `EventsListenable`

example/pubspec.lock

@@ -162,7 +162,7 @@ packages:
       name: logging
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "1.0.1"
+    version: "1.0.2"
   matcher:
     dependency: transitive
     description:
@@ -268,13 +268,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "5.0.0"
-  quiver:
-    dependency: transitive
-    description:
-      name: quiver
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "3.0.1"
   shared_preferences:
     dependency: "direct main"
     description:
@@ -371,13 +364,6 @@ packages:
       url: "https://pub.dartlang.org"
     source: hosted
     version: "0.4.2"
-  tuple:
-    dependency: transitive
-    description:
-      name: tuple
-      url: "https://pub.dartlang.org"
-    source: hosted
-    version: "2.0.0"
   typed_data:
     dependency: transitive
     description: