Bug 15812: Use patron search in place of circ search

Bug 15812: Use patron search in place of circ search

The 'Checkout' search hijacks some of the DataTables searching code used for 'Search patrons'
Rather than try to implement the search again on another page, we can simply send the user
to the patron search if the cardnumber is not found

Additionally, this patch adds a 'Check out' button to the patron search results to allow
going to checkotus directly

To test:
1 - Apply patch
2 - Perform a 'Checkout' search from the header
3 - Note that:
    For a cardnumber, you are redirected directly to checkouts page for the borrower
    For a search with one result, you are redirected directly to the checkout page for the borrower
    For a search with many results, you are redirected to the patron search results
    and there is a 'Checkout' button under the cardnumber
4 - Confirm circulation page works as expected (i.e. checkout to a patron)

Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: George Williams <george@nekls.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>