Change mail contrib date/times to display in local time based on style timezone setting

[chiizujin]

Brief overview of PR changes/additions

The mail (contrib) command currently shows mail date/times in UTC. This changes the date/times to the local time zone based on the setting in style.

Motivation for adding to Evennia

Show local time for mail.

Other info

UTC:

>mail
------------------------------------------------------------------------------
 ID    From              Subject                           Arrived            
------------------------------------------------------------------------------
 1     Jazri             Test                              14:33:34     -     
------------------------------------------------------------------------------
>mail/read 1
------------------------------------------------------------------------------
From: Jazri
Sent: Apr 12, 2024 - 14:33:34
Subject: Test
------------------------------------------------------------------------------
Test.
------------------------------------------------------------------------------

Local time:

>mail
------------------------------------------------------------------------------
 ID    From              Subject                           Arrived            
------------------------------------------------------------------------------
 1     Jazri             Test                              00:33:34     -     
------------------------------------------------------------------------------
>mail/read 1
------------------------------------------------------------------------------
From: Jazri
Sent: Apr 12, 2024 - 00:33:34
Subject: Test
------------------------------------------------------------------------------
Test.
------------------------------------------------------------------------------

[Griatch]

I think this is affected by the same issue as the page datetime PR - the server is not always using UTC.