Bug 26584: Remove unused C4::Acquisition::CloseBasket function

Bug 26584: Remove unused C4::Acquisition::CloseBasket function

This patch makes code use the new Koha::Acquisition::Basket->close
method and makes CloseBasket obsolete.

It then removes it, and adapts the few places in which it was used.

1. Apply this patch
2. Run:
   $ kshell
  k$ git diff origin/master --name-only | grep -e '\.t$' | xargs prove
=> SUCCESS: Tests pass!
3. Try playing with baskets, closing them
=> SUCCESS: All works as expected!
4. Sign off :-D

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>