Fix for Bug 6818 - acquisitions basket groups could use some design work

Fix for Bug 6818 - acquisitions basket groups could use some design work

I've made changes to the basket grouping interface to bring it
in line with other interfaces in Koha. I think it's better to
keep things following a consistent pattern.

On the page which lists basket groups:

- Basket groups listed in a table instead of as custom-styled lists
- Buttons use standard style
- Tabs are generated by jQuery

On the page for managing baskets in a group:

- Markup has been revised to be more consistent with established
  patterns.
- Corrections have been made for validity

On the basket view page:

- Display of data has been streamlined a little bit
- An option has been added to the "Basket group" dropdown
  for adding a new group
- Markup has been corrected for validity and consistency

Signed-off-by: Katrin Fischer <Katrin.Fischer.83@web.de>
1) Basket group page
The blue is gone and the new buttons  are much better
readable than before.

2) Basket grouping page
Works.

3) Basket view page
I like the new option to create a new group from here.
Nice improvement to the workflow!
I removed a spare 'td' from line 264.

Signed-off-by: Paul Poulain <paul.poulain@biblibre.com>