Bug 29519: Allow resolution of claims return at checkin

Bug 29519: Allow resolution of claims return at checkin

Add a 'Resolve' button in the alert dialogue that is displayed when a
lost item with a return claim is checked in. The button will trigger the
usual resolution modal allowing the user to pick their resolution.

This patch splits the resolution modal out of checkouts.js and
checkouts-table.inc so it can be used outside of the checkouts table.
We then reload it, optionally based upon the presence of the claims
preference, where needed.  This has the added benefit that it saves a
little bit of page load data in cases where the feature is not enabled.

Test plan
1. As we alter the file locations of the resolution handling code we
   need to test that normal claims functionality continue to work as
   expected.
2. Test the new functoinality by checking in an item that has been
   claimed as returned (but not yet resolved). The dialogue box should
   now contain a 'resolve' button next to each claimant and clicking
   upon it should trigger the resolution modal where the librarian can
   subsequently pick the resolution and submit it.

Signed-off-by: Andrew Fuerste-Henry <andrew@bywatersolutions.com>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>