Revert batch size

[Pl217]

Even though using the maximum theoretical limit (defined by PG_MAX_QUERY_PARAMS) works, it takes a significant performance toll. The change came after this comment, in which I suggested exploring the batch size increase.

I noticed the slowness when trying to use this query:

query {
  searchFlows(
    limit: 50
    sortField: "flow.updatedAt"
    sortOrder: "DESC"
    flowFilters: {activeStatus: true}
    flowObjectFilters: [{objectID: 4396, direction: "source", objectType: "organization"}]
    includeChildrenOfParkedFlows: true
  ) {
    total
  }
}

With batch size of 1000, this takes ~13 seconds and with maximum theoretical batch size it never completes (I let it for about 20 mins) and needed shm_size: 1g on PostgreSQL container.

[unocha-hpc]

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