Improve the queries used to fetch users via the Search Users screen to prevent Wiki threads from being blocked for long periods of time

For large instances with thousands of LDAP users, the "Show all Users" screen or for a search term with a number of results, can take a long time to return results, blocking a thread for several minutes. This behavior is not just associated with "Manage Users" admin function. The issue exists with anywhere the User Search screen appears - this is both from Admin screens and User screens.
A large number of queries in batches of 100s are repeatedly issued to the LDAP server for each page of the user list. It appears like for the first set, it uses 100 reads, for the second 200, for the third 300 and so on... This should be improved to reduce the need for repeated queries.

As a workaround, ensure that the "Administration->General Configuration->Append wildcards to user and group searches" property has been turned OFF to limit search to exact terms. Though this work around does not stop users from impacting system performance by manually typing wildcards into the search string.