Bug 19502: Limit pagination to first 10000 results when using ES

Bug 19502: Limit pagination to first 10000 results when using ES

This patch is to avoid hitting an error page. We should eventually make the
max number returned configurable for ES.

To test:
1 - Have Koha running ES with 10,000+ records
2 - Search for '*'
3 - Click 'Last' to view last page of results
4 - 'Cannot perform search' error
5 - Apply patch
6 - Search again
7 - View 'Last' page
8 - No error, you go to the last of 10000
9 - Note the warning above the pagination buttons

Signed-off-by: Séverine QUEUNE <severine.queune@bulac.fr>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Alex Arnaud <alex.arnaud@biblibre.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>