Search for users REST API returns incorrect totalSize

Issue Summary

Search for users REST API is not returning the correct number of total search results so it is not possible to know from the search response whether there are more paginated results

Steps to Reproduce

1. Make a call to `rest/api/search/user?cql=type=user&limit=n` where n is set to 2
2. Repeat the previous step, but with a higher number for n

Expected Results

`totalSize` should be set to the number of results that exist for the search query, not the number of results returned

Actual Results

Regardless of what is passed in for `limit`, the `totalSize` returned is always incorrect (i.e. usually just matches the number of results returned)

Workaround

Keep requesting the next set of search results until there are no more