REST API search for users using "allConfigured" source should not be limited to 100 entries

Currently the user search REST API will limit responses to 100 users if a source other than "default" is used. This is done to prevent the API from causing out of memory errors when very large external authentications systems are used:  NEXUS-13071

This makes some sense for external systems like LDAP and Crowd.  It does not make sense for the "allConfigured" source:

http://localhost:8081/service/rest/v1/security/users?source=allConfigured

Users from that source have been explicitly granted roles, and it should be possible to retrieve all of them.