Bug 16305 - Remove the use of "onclick" from transport cost matrix

Bug 16305 - Remove the use of "onclick" from transport cost matrix

This patch updates the transport cost matrix template to eliminate the
use of event attributes (onclick and onblur) in favor of JS separate
from the markup.

To test, apply the patch and go to Administration -> Transport cost
matrix.

- Click in any table cell. Form fields in the cell should activate.
- Check and uncheck the "disable" checkbox. The form field should be
  correctly disabled and enabled.
- Fill various enabled fields and submit the form to confirm that data
  is saved correctly.

Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>