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/renderer/components/App.tsx

@@ -26,19 +26,11 @@ const theme = createTheme({
     },
     secondary: indigo,
   },
-  transitions: {
-    create: () => "none",
-  },
-  props: {
-    MuiButtonBase: {
-      disableRipple: true,
-    },
-  },
   typography: {
     overline: {
-      textTransform: 'none', // This prevents the text from being all caps
+      textTransform: "none", // This prevents the text from being all caps
     },
-  }
+  },
 });
 
 function InnerContent() {