Prevent big page offset

[hei-teacher]

Our current pagination is translated into offset-limit pagination by Postgres.
The more P=page*pageSize increase, the longer Postgres takes to process the request.
In particular, P could lead to a full scan.
To prevent this, P should be bounded.
Eg: P_MAX=1_000 ensures that a query will never scan more than P_MAX+MAX_PAGE_SIZE.
P_MAX=1_000 is large enough to cover all the use cases of the API.
* We don't expect consumers to dump the whole database
* Consumers are only expected to find users by weak comparison on
* ref
* firstname
* name

[hei-teacher]

Use the BoundedPageSize for pagination.