Add lobby and scene managers, implement scene switching with fade in/out

Assets/Scenes/Lobby.unity

@@ -8206,6 +8206,7 @@ GameObject:
   m_Component:
   - component: {fileID: 669203337}
   - component: {fileID: 669203336}
+  - component: {fileID: 669203338}
   m_Layer: 0
   m_Name: SceneContext
   m_TagString: Untagged
@@ -8226,7 +8227,8 @@ MonoBehaviour:
   m_Name: 
   m_EditorClassIdentifier: 
   _scriptableObjectInstallers: []
-  _monoInstallers: []
+  _monoInstallers:
+  - {fileID: 669203338}
   _installerPrefabs: []
   _autoRun: 1
   OnPreInstall:
@@ -8259,6 +8261,18 @@ Transform:
   m_Children: []
   m_Father: {fileID: 0}
   m_LocalEulerAnglesHint: {x: 0, y: 0, z: 0}
+--- !u!114 &669203338
+MonoBehaviour:
+  m_ObjectHideFlags: 0
+  m_CorrespondingSourceObject: {fileID: 0}
+  m_PrefabInstance: {fileID: 0}
+  m_PrefabAsset: {fileID: 0}
+  m_GameObject: {fileID: 669203335}
+  m_Enabled: 1
+  m_EditorHideFlags: 0
+  m_Script: {fileID: 11500000, guid: a37c700de6d3a4a4385fcc8bcd15405f, type: 3}
+  m_Name: 
+  m_EditorClassIdentifier: 
 --- !u!1001 &673324911
 PrefabInstance:
   m_ObjectHideFlags: 0