Batch alerts sending

This is to avoid sending too many alerts on a new datasource addition or batch edit.

Some points:
- Might need a new table to manage this batch send.
- Would be managed from a queue function call.

Start by tracing the queue function used for new datasource additions and batch edits; the issue does not name specific files or tests. Determine how alerts are currently sent, then define a batching mechanism, including whether a new table is needed, and verify that these operations no longer send too many alerts.

Written by the indexing model from the issue text.