Big batch of UI updates (#276)

* Replace react-native-root-toast with a custom toast that fits the visual style

* Tune dark mode colors

* Tune colors a bit more

* Move the reply prompt to a fixed position in the footer

* Fully hide muted posts but give a control to show anyway (close #270)

* Improve thread rendering (better clarity on reply lines)

* Add follower/following counts to side menu

* Fix issues with display name overflows

src/view/shell/mobile/index.tsx

@@ -157,7 +157,7 @@ export const MobileShell: React.FC = observer(() => {
   }
 
   const screenBg = {
-    backgroundColor: theme.colorScheme === 'dark' ? colors.gray7 : colors.gray1,
+    backgroundColor: theme.colorScheme === 'dark' ? colors.black : colors.gray1,
   }
   return (
     <View testID="mobileShellView" style={[styles.outerContainer, pal.view]}>
@@ -202,13 +202,7 @@ export const MobileShell: React.FC = observer(() => {
                       style={[
                         s.h100pct,
                         screenBg,
-                        current
-                          ? [
-                              swipeTransform,
-                              // tabMenuTransform, TODO
-                              // isRunningNewTabAnim ? newTabTransform : undefined, TODO
-                            ]
-                          : undefined,
+                        current ? [swipeTransform] : undefined,
                       ]}>
                       <ErrorBoundary>
                         <Com