Bug 11056: Delete dead code in basketgroup.pl

Bug 11056: Delete dead code in basketgroup.pl

In basketgroup.pl, some code is supposed to be executed if
$op = "validate".  But this value is no longer assigned to
the $op variable since 2009.

This patch suppressed dead code, along with parseinputbaskets
and parseinputbasketgroups subs, which are obsolete.

No functional changes expected

Regression test :
* Check basketgroup are shown as before the patch, and can be closed
 and reopened.
* Check you can add or remove a basket from a basketgroup, and change
  information about it (like delivery place)
* Check you can create a basketgroup when you close a basket.

Signed-off-by: Jonathan Druart <jonathan.druart@biblibre.com>
The following commands return nothing:
- grep validate acqui/basketgroup.tt
- grep -R basketgroup.pl -C 2 | grep validate
- git grep parseinputbaskets
- git grep parseinputbasketgroups
- git grep basketgroup.pl | grep validate

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>