“Autofill” and “Autofill and Save” buttons for the browser extension Vault (#1367)

* Add autofill button to View cipher screen in Vault

* Add Autofill and Save button to View screen in Vault

* disable Vault Autofill buttons in popout

* tidy up 'autofill from vault' features as per feedback in PR #1367

Includes:
- remove duplicate code
- better handling of error and success messages

src/_locales/en/messages.json

@@ -1299,5 +1299,14 @@
   },
   "vaultTimeoutLogOutConfirmationTitle": {
     "message": "Timeout Action Confirmation"
+  },
+  "autoFillAndSave": {
+    "message": "Auto-fill and Save"
+  },
+  "savedUri": {
+    "message": "Auto-filled and Saved Item"
+  },
+  "autoFillSuccess": {
+    "message": "Auto-filled Item"
   }
 }