Raise Webhook URI length limit from 255 to 2048 master
Summary: 2048 is arbitrary (as 255 was) and only enforced in the UI but not on a DB level. Closes T16303 Test Plan: * Run `./bin/storage upgrade` * Check `./bin/storage status` * Check `EXPLAIN phabricator_herald.herald_webhook;` and/or http://phorge.localhost/config/database/localhost/phabricator_herald/herald_webhook/ before and after * Go to http://phorge.localhost/herald/webhook/edit/form/default/ and enter a long URI in the `URI` field before and after Reviewers: O1 Blessed Committers, avivey Reviewed By: O1 Blessed Committers, avivey Subscribers: avivey, tobiaswiese, valerio.bozzolan, Matthew, Cigaryno Maniphest Tasks: T16303 Differential Revision: https://we.phorge.it/D26462