Clone $ShowHistory config support into the two RTIR Displays

This allows RTIR to use the RT default of "load the page, then make a
request to load the history" which makes page loads seem much faster.

RTIR needs to set a number of custom paths on history entries, so use
the callback from 4.2/tickethistory-callback to do so.

Resolves issues #29730
Collapsed hasn't been used since RTIR 1.0

RTIR had a custom history display widget that was removed prior to 2.4
Merge branch '3.2/defer-history-loading'