#53 - Refactored various components:

- updated the authentication coordinator to use async await
- replaced the UserSession with a ClientProxy (similar to the RoomProxy)
- renamed `completion` to `callback` on the coordinators and view models
- renamed `viewModelResult` to `viewModelAction`
- introduced back UserSession as a user specific service container

Tools/Scripts/Templates/SimpleScreenExample/ElementX/TemplateSimpleScreenModels.swift

@@ -47,7 +47,7 @@ extension TemplateSimpleScreenPromptType: Identifiable, CaseIterable {
 
 // MARK: View model
 
-enum TemplateSimpleScreenViewModelResult {
+enum TemplateSimpleScreenViewModelAction {
     case accept
     case cancel
 }