Add Authentication Flow WIP.

- Add Registration Screen.
- Add Server Selection Screen.
- Rename AuthenticationCoordinator to LegacyAuthenticationCoordinator.
- Add AuthenticationService and RegistrationWizard.
- Async extensions.
- Add global white and EMS colors to the themes.
- Add tests for server selection and registration screens.
- Accessibility and iPad layout tweaks.
- Remove MainActor from Auth Coordinators/VMs/Views.
(It broke the protocol conformances so now the methods and properties are marked individually.)

DesignKit/Source/ColorValues.swift

@@ -46,5 +46,9 @@ public struct ColorValues: Colors {
     
     public let background: UIColor
     
+    public let white: UIColor
+    
+    public let ems: UIColor
+    
     public let namesAndAvatars: [UIColor]
 }

DesignKit/Source/Colors.swift

@@ -55,7 +55,7 @@ public protocol Colors {
     /// Separating line
     var separator: ColorType { get }
     
-    //  Cards, tiles
+    /// Cards, tiles
     var tile: ColorType { get }
     
     /// Top navigation background on iOS
@@ -64,6 +64,12 @@ public protocol Colors {
     /// Background UI color
     var background: ColorType { get }
     
+    /// Global color: The color white.
+    var white: ColorType { get }
+    
+    /// Global color: The EMS brand's purple colour.
+    var ems: ColorType { get }
+    
     /// - Names in chat timeline
     /// - Avatars default states that include first name letter
     var namesAndAvatars: [ColorType] { get }

DesignKit/Source/ColorsSwiftUI.swift

@@ -47,6 +47,10 @@ public struct ColorSwiftUI: Colors {
     
     public let background: Color
     
+    public var white: Color
+    
+    public var ems: Color
+    
     public let namesAndAvatars: [Color]
     
     init(values: ColorValues) {
@@ -62,6 +66,8 @@ public struct ColorSwiftUI: Colors {
         tile = Color(values.tile)
         navigation = Color(values.navigation)
         background = Color(values.background)
+        white = Color(values.white)
+        ems = Color(values.ems)
         namesAndAvatars = values.namesAndAvatars.map({ Color($0) })
     }
 }