Bug 33913: (QA follow-up) Move variables into strings

Bug 33913: (QA follow-up) Move variables into strings

To test:

1) Checking out to {patron}
* Search for any patron
* Click on cardnumber in patron search results
* Verify that page title reads correctly and includes patron's name

2) Batch check out to {patron}
* Activate BatchCheckouts system preference
* Check all patron categories for BatchCheckoutsValidCategories
* Go to any patron account
* Click on batch checkout tab
* Verify that the page title reads correctly and includes patron's name

3) Place a hold on {title}
* Search for a record with items in the staff interface catalog
* Click on 'place holds'
* Verify that the page title reads correctly and includes the title of the record

4) Overdues as of {date}
* Set DateFormat system preference to any other than default
* Go to circulation > overdues
* Verify the page title includes today's date in the correct format

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>