feat(mobile): Add people list to exit bottom sheet (#6717)

* feat(mobile): Define constants as 'const'

* feat(mobile): Add people list to asset bottom sheet

Add a list of people per asset in the exif bottom sheet, like on the
web.

Currently the list of people is loaded by making a request each time to
the server. This is the MVP approach.
In the future, the people information can be synced like we're doing
with the assets.

* styling

---------

Co-authored-by: Alex Tran <alex.tran1502@gmail.com>

mobile/lib/modules/asset_viewer/views/gallery_viewer.dart

@@ -148,9 +148,9 @@ class GalleryViewerPage extends HookConsumerWidget {
     }
 
     void handleSwipeUpDown(DragUpdateDetails details) {
-      int sensitivity = 15;
-      int dxThreshold = 50;
-      double ratioThreshold = 3.0;
+      const int sensitivity = 15;
+      const int dxThreshold = 50;
+      const double ratioThreshold = 3.0;
 
       if (isZoomed.value) {
         return;