Bug 31356: Use hold expiration date instead of adding days to the waiting date

Bug 31356: Use hold expiration date instead of adding days to the waiting date

The Talking Tech outbound script currently just adds the
ReservesMaxPickUpDelay to the waiting date to calculate the
"expiration date", but it should use the actual hold expiration
date which may differ from this naive calculation based on
various system preference values.

Test Plan:
1) Create a holiday for tomorrow
2) Set ReservesMaxPickUpDelay to 5
3) Set "Days mode" to "Same week day"
4) Enable ExcludeHolidaysFromMaxPickUpDelay
5) Enable TalkingTechItivaPhoneNotification
6) Create a hold and fill the hold so it is waiting
7) Enable "Hold filled" phone notices for that patron
8) Create a 'phone' version of the HOLD notice
9) Run ./misc/cronjobs/thirdparty/TalkingTech_itiva_outbound.pl --type RESERVE -w 0
10) Note the output has the expiration date ( 15th colume ) 5 days from now which is *not* the hold's expiration date
11) Apply this patch
12) Repeat the command from step 9
13) Note the expiration date column now matches the holds actual expiration date!

Signed-off-by: Kyle Hall <kyle@bywatersolutions.com>
Signed-off-by: Joonas Kylmälä <joonas.kylmala@iki.fi>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>