[MM-39851] Add CRUD methods for user sessions to plugin API (#18958)

i18n/en.json

@@ -5983,6 +5983,10 @@
     "id": "app.session.analytics_session_count.app_error",
     "translation": "Unable to count the sessions."
   },
+  {
+    "id": "app.session.extend_session_expiry.app_error",
+    "translation": "Unable to extend session length"
+  },
   {
     "id": "app.session.get.app_error",
     "translation": "We encountered an error finding the session."