Bug: indexer_allocations limited to first 1000

[hopeyen]

Describe the bug

https://github.com/graphprotocol/indexer-rs/blob/main/common/src/allocations/monitor.rs#L68
This query string limits indexer_allocation query to first 1000 active allocations with no pagination. Shown by an instance that there exists indexer with 1000+ active allocations, this function fails to grab all eligible allocations for monitoring.

Expected behavior
Add pagination to the query and ensure all active allocations for an indexer are monitored.

Additional context
Uncovered by the same issue on TS version of indexer-service

[aasseman]

Corresponding fix in the TS version: graphprotocol/indexer#862