Bug 10533: move JavaScript functions for basket groups to a separate file

This patch moves JavaScript functions used for managing basket groups
to a file.  This has the effect of putting the last (active) use of
the YUI JavaScript library by the staff interface in one file:

  koha-tmpl/intranet-tmpl/prog/en/js/basketgroup.js

Test plan:
- Try all actions for basketgroup ( drag/drop, add, delete, close, print,
reopen, edit, export as csv).
- Check that there is no regression on others acquisition pages:
  * acqui/neworderempty.tt
  * acqui/uncertainprice.tt
  * acqui/addorderiso2709.tt
  * acqui/basketheader.tt
  * admin/aqbudgets.tt
  * admin/aqcontract.tt
  * admin/aqbudgetperiods.tt
  * admin/aqplan.tt
  * suggestion/suggestion.tt

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
Works as described, passes all tests and QA script.

Signed-off-by: Galen Charlton <gmc@esilibrary.com>
(cherry picked from commit b8f1b43966d178174583c7a3e0c36e58f988b161)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>