Bug 29893: Prevent ES mappings UI to remove hidden rows

Bug 29893: Prevent ES mappings UI to remove hidden rows

If you are editing ES mappings and you use the DataTable filtering option,
the table won't contain all the mappings you have in the DB.
If the form is submitted they will be removed and data will be lost!

Test plan:
Edit ES mappings, filter and submit the form.
Confirm that the table are redrawn before the form submission which
prevent data loss

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>