support getting count without querying

[snopoke]

Summary

When exporting large datasets having the progress output is very helpful. For the ICDS data export I added progress output for the SQL exporter https://github.com/dimagi/commcare-icds/pull/157/files#diff-2299e47508434b48a9b377144efb0fe3e4f283b35ce6539b3b641a968b5b2251R150

This change moves the counting to the builders and filters so that the SQL count query can be skipped if the filter already knows the total count (e.g. when filtering by ID or username).

Safety Assurance

• Risk label is set correctly
• The set of people pinged as reviewers is appropriate for the level of risk of the change
• If QA is part of the safety story, the "Awaiting QA" label is used
• I am certain that this PR will not introduce a regression for the reasons below

Rollback instructions

• This PR can be reverted after deploy with no further considerations