Bug 27405: (follow up) Updates to accommodate currency entry

Bug 27405: (follow up) Updates to accommodate currency entry

This patch makes two modifications to allow the entry of
currency strings (for example, 1.25) so that it is consistent with other
payment entry forms.

- Inputmode changed to "decimal"
- Regex pattern changed to "^\d+(\.\d{2})?$" as found in
  admin/debit_types.tt

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>