Add loading view

RiotSwiftUI/Modules/Room/PollHistory/PollHistoryModels.swift

@@ -27,16 +27,43 @@ enum PollHistoryMode: CaseIterable {
     case past
 }
 
+enum PollHistoryLoadingState {
+    case idle
+    case loading(firstLoad: Bool)
+}
+
+extension PollHistoryLoadingState {
+    var isLoadingOnLanding: Bool {
+        switch self {
+        case .idle:
+            return false
+        case .loading(let firstLoad):
+            return firstLoad
+        }
+    }
+    
+    var isLoading: Bool {
+        switch self {
+        case .idle:
+            return false
+        case .loading:
+            return true
+        }
+    }
+}
+
 struct PollHistoryViewBindings {
     var mode: PollHistoryMode
 }
 
 struct PollHistoryViewState: BindableState {
-    init(mode: PollHistoryMode) {
+    init(mode: PollHistoryMode, loadingState: PollHistoryLoadingState) {
         bindings = .init(mode: mode)
+        self.loadingState = loadingState
     }
     
     var bindings: PollHistoryViewBindings
+    var loadingState: PollHistoryLoadingState
     var polls: [TimelinePollDetails] = []
 }