Bug 32746: Standardize structure around action fieldsets in acquisitions

Bug 32746: Standardize structure around action fieldsets in acquisitions

This patch updates acquisitions templates so that fieldsets with the
"action" class are placed outside the form's main fieldset. A couple of
minor changes have been made to related CSS.

To test, apply the patch and rebuild the staff interface CSS. Go to
acquisitions and check the following pages to confirm that changes to
form structure look correct:

- Open the "Late orders" page from the left-hand sidebar menu and check
  the form in the sidebar.
- Open the "Orders search" form in the search header and submit the form
  without specifying any search criteria. This should bring up a blank
  orders search form.
- Open the "Invoices" page from the left-hand sidebar menu. Check the
  form in the sidebar.
  - Perform an invoice search which will return results.
  - View one of the invoices returned by your search.
  - On the invoice detail age, the "Save" button associated with the
    invoice details at the top should look correct.
  - There should be a box below that with the heading "Adjustments" and
    a link to add an adjustment.
  - When you click "Add an adjustment," a form should be displayed with
    the correct controls at the bottom. Clicking "Cancel" should hide
    the form.
  - Click the "Manage invoice files" link, and check the form on that
    page.
- Locate a vendor and view its details.
  - Check the "Uncertain prices" page, linked from the menu in the
    left-hand sidebar.
  - Open the "Baskets" page from the left-hand sidebar. Click the "Add
    to basket" button for one of the existing baskets.
  - Click "From existing orders (copy)". Check that this form looks
    correct.
  - Open the "Basket groups" page from the left-hand sidebar menu.
    - Click "New basket group" and check that form.

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>