feat: prompt to confirm discard editor changes (#2948)

* chore: update he.json

* feat: prompt to confirm discard editor changes

---------

Co-authored-by: Oleg Lobanov <oleg@lobanov.me>

frontend/src/i18n/en.json

@@ -38,7 +38,8 @@
     "update": "Update",
     "upload": "Upload",
     "openFile": "Open file",
-    "continue": "Continue"
+    "continue": "Continue",
+    "discardChanges": "Discard"
   },
   "download": {
     "downloadFile": "Download File",
@@ -162,7 +163,8 @@
     "uploadFiles": "Uploading {files} files...",
     "uploadMessage": "Select an option to upload.",
     "optionalPassword": "Optional password",
-    "resolution": "Resolution"
+    "resolution": "Resolution",
+    "discardEditorChanges": "Are you sure you wish to discard the changes you've made?"
   },
   "search": {
     "images": "Images",