feat(tauri): Initialize Context in background (#59)

This PR does the following:
- The Context (including Bitcoin wallet, Monero wallet, ...) is initialized in the background. This allows the window to be displayed instantly upon startup.
- Host sends events to Guest about progress of Context initialization. Those events are used to display an alert in the navigation bar.
- If a Tauri command is invoked which requires the Context to be available, an error will be returned
- As soon as the Context becomes available the `Guest` requests the history and Bitcoin balance
- Re-enables Material UI animations

src-gui/src/store/hooks.ts

@@ -23,6 +23,10 @@ export function useIsSwapRunning() {
   );
 }
 
+export function useIsContextAvailable() {
+  return useAppSelector((state) => state.rpc.status?.type === "Available");
+}
+
 export function useSwapInfo(swapId: string | null) {
   return useAppSelector((state) =>
     swapId ? (state.rpc.state.swapInfos[swapId] ?? null) : null,