vector-im/element-x-ios/issues/53 - Adopt MainActors, dispatch heavy operations do detached tasks and ensure combine publisher call back on the right queue

ElementX/Sources/Other/Coordinator.swift

@@ -19,6 +19,7 @@ import UIKit
 /// Protocol describing a [Coordinator](http://khanlou.com/2015/10/coordinators-redux/).
 /// Coordinators are the objects which control the navigation flow of the application.
 /// It helps to isolate and reuse view controllers and pass dependencies down the navigation hierarchy.
+@MainActor
 protocol Coordinator: AnyObject {
     
     /// Starts job of the coordinator.

ElementX/Sources/Other/Routers/NavigationRouterStoreProtocol.swift

@@ -17,6 +17,7 @@
 import UIKit
 
 /// `NavigationRouterStoreProtocol` describes a structure that enables to get a NavigationRouter from a UINavigationController instance.
+@MainActor
 protocol NavigationRouterStoreProtocol {
     
     /// Gets the existing navigation router for the supplied controller, creating a new one if it doesn't yet exist.

ElementX/Sources/Other/Routers/NavigationRouterType.swift

@@ -18,6 +18,7 @@ import UIKit
 
 /// Protocol describing a router that wraps a UINavigationController and add convenient completion handlers. Completions are called when a Presentable is removed.
 /// Routers are used to be passed between coordinators. They handles only `physical` navigation.
+@MainActor
 protocol NavigationRouterType: AnyObject, Presentable {
 
     /// Present modally a view controller on the navigation controller

ElementX/Sources/Other/Routers/Presentable.swift

@@ -17,6 +17,7 @@
 import UIKit
 
 /// Protocol used to pass UIViewControllers to routers
+@MainActor
 protocol Presentable {
     func toPresentable() -> UIViewController
 }

ElementX/Sources/Other/Routers/RootRouterType.swift

@@ -18,6 +18,7 @@ import UIKit
 
 /// Protocol describing a router that wraps the root navigation of the application.
 /// Routers are used to be passed between coordinators. They handles only `physical` navigation.
+@MainActor
 protocol RootRouterType: AnyObject {          
     
     /// Update the root view controller

ElementX/Sources/Other/SwiftUI/ViewModel/StateStoreViewModel.swift

@@ -30,6 +30,7 @@ import Combine
 /// It provides a nice layer of consistency and also safety. As we are not passing the `ViewModel` to the view directly, shortcuts/hacks
 /// can't be made into the `ViewModel`.
 @dynamicMemberLookup
+@MainActor
 class ViewModelContext<ViewState: BindableState, ViewAction>: ObservableObject {
     // MARK: - Properties
 
@@ -70,6 +71,7 @@ class ViewModelContext<ViewState: BindableState, ViewAction>: ObservableObject {
 /// a specific portion of state that can be safely bound to.
 /// If we decide to add more features to our state management (like doing state processing off the main thread)
 /// we can do it in this centralised place.
+@MainActor
 class StateStoreViewModel<State: BindableState, ViewAction> {
 
     typealias Context = ViewModelContext<State, ViewAction>