Remove code_sharing and place_tracker, cleanup repo (#2831)

Fixes #2818, #2523, #2528

desktop_photo_search/material/lib/src/widgets/split.dart

@@ -19,8 +19,6 @@ import 'package:flutter/material.dart';
 ///
 /// The user can drag the widget with key [dividerKey] to change
 /// the space allocated between [firstChild] and [secondChild].
-// TODO(djshuckerow): introduce support for a minimum fraction a child
-//                    is allowed.
 class Split extends StatefulWidget {
   /// Builds a split oriented along [axis].
   const Split({
@@ -125,12 +123,6 @@ class _SplitState extends State<Split> {
       });
     }
 
-    // TODO(https://github.com/flutter/flutter/issues/43747): use an icon.
-    // The material icon for a drag handle is not currently available.
-    // For now, draw an indicator that is 3 lines running in the direction
-    // of the main axis, like a hamburger menu.
-    // TODO(https://github.com/flutter/devtools/issues/1265): update mouse
-    // to indicate that this is resizable.
     final dragIndicator = Flex(
       direction: isHorizontal ? Axis.vertical : Axis.horizontal,
       mainAxisSize: MainAxisSize.min,