Bug 29926: Add ability for superlibrarian to view/edit password expiration

Bug 29926: Add ability for superlibrarian to view/edit password expiration

To  test:
 1 - Sign in as a superlibrarian
 2 - Find a patron account with no password expiration set
 3 - View member detials
 4 - note expiration says 'Never'
 5 - Edit patron
 6 - Set patron expiration
 7- Save
 8 - View details, confirm password expiration shows correctly
 9 - Sign in as non-superlibrarian
10 - Confirm you don't see expirationdate on details page
11 - Edit patron and confirm password expiration does not show
12 - Edit HTML and confirm you epxiration date not saved
     <input type="text" name="password_expiration_date" value="2052-05-02">

Signed-off-by: Bob Bennhoff <bbennhoff@clicweb.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>