Bug 14929: Fix missing display of help page in contract management

Bug 14929: Fix missing display of help page in contract management

This patch renames / moves  the file
koha-tmpl/intranet-tmpl/prog/en/modules/help/acqui/acqcontract.tt
to
koha-tmpl/intranet-tmpl/prog/en/modules/help/admin/aqcontract.tt

To test:
- Go to Home > Acquisition > [Vendor] > Contracts
  (/cgi-bin/koha/admin/aqcontract.pl?booksellerid=XXXX)
- Verify that Help displays as appropriate.

Signed-off-by: Magnus Enger <magnus@libriotech.no>
Works as advertised. All the tabs similar to "Contracts" have
working help pages.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@unc.edu.ar>