R1:22b075df9716

Fix "ONLY_FULL_GROUP_BY" issue in SystemAction queries

Summary: Ref T13404. This query is invalid under "sql_mode=ONLY_FULL_GROUP_BY". Rewrite it to avoid interacting with `actorIdentity` at all; this is a little more robust in the presence of weird data and not really more complicated.

Test Plan:
- Enabled "ONLY_FULL_GROUP_BY".
- Hit system actions (e.g., login).
- Before: error.
- After: clean login.
- Tried to login with a bad password many times in a row, got properly limited by the…