wire in a timestamp for Client-Lost so rlm_detail does not use the epoch

[jimdigriz]

This PR resolves during Post-Auth-Type Client-Lost the fake request passed to rlm_detail does not have request->packet->timestamp populated so we end up jumping back to the epoch:

(5) Using Post-Auth-Type Client-Lost
(5) # Executing group from file /etc/freeradius/sites-enabled/default
(5)   Post-Auth-Type Client-Lost {
(5) [snipped]
(5) detail_kitchensink: EXPAND .../detail/kitchensink/%Y/%m/%d/%H/%G
(5) detail_kitchensink:    --> .../detail/kitchensink/1970/01/01/00/00
(5) detail_kitchensink: .../detail/kitchensink/%Y/%m/%d/%H/%G expands to .../detail/kitchensink/1970/01/01/00/00 <---------
(5) detail_kitchensink: EXPAND ts0=%l.%M ts=%c.%C reqid=%I reqno=%n
(5) detail_kitchensink:    --> ts0=0.000000 ts=1719580464.298668 reqid=-1 reqno=5
(5)       [detail_kitchensink] = ok

On a related note, I notice that cleanup on an idle server does not take place till another packet is received. Is this intention? Should another wakeup be installed to clean this up in a timely fashion and get this event captured in the logging downstream?