feat: delete active annotation using backspace/delete key (#4722)

Co-authored-by: scouser <sharukh@Sharukhs-MacBook-Pro.local>

platform/core/src/defaults/hotkeyBindings.js

@@ -173,6 +173,10 @@ const bindings = [
     label: 'W/L Preset 5',
     keys: ['5'],
   },
+  {
+    commandName: 'deleteActiveAnnotation',
+    keys: ['backspace'],
+  },
   // These don't exist, so don't try applying them....
   // {
   //   commandName: 'setWindowLevel',