Address PR comments.

Log errors before throwing.
Remove white colour.
Remove AuthenticationCoordinatorState added during rebase.

RiotSwiftUI/Modules/Authentication/Common/Service/MatrixSDK/RegistrationModels.swift

@@ -47,6 +47,7 @@ struct RegistrationParameters: Codable {
         let jsonData = try JSONEncoder().encode(self)
         let object = try JSONSerialization.jsonObject(with: jsonData)
         guard let dictionary = object as? [String: Any] else {
+            MXLog.error("[RegistrationParameters] dictionary: Unexpected type decoded \(type(of: object)). Expected a Dictionary.")
             throw AuthenticationError.dictionaryError
         }