Bug 18887: Port max_holds rules to new CirculationRules system

Bug 18887: Port max_holds rules to new CirculationRules system

This is the first step in the circulation rules revamp as detailed
in the RFF https://wiki.koha-community.org/wiki/Circulation_Rules_Interface_and_Backend_Revamp_RFC

This patch moves the recent max_holds rule to the new circulation_rules table.

Test Plan:
1) Apply this patch
2) Run updatedatabase.pl
3) Go to the circ rules editor, note the new max holds rules
   by patron category in the "Checkout limit by patron category".
   ( Should we rename this section? )
4) Create find a patron that is allowed to place a hold, count the
   number of holds that patron has. Lets make that number 'X'.
5) Set the new max holds rule to X for "All libraries"
6) Note the patron can no longer place another hold
7) Set the new max holds rule to X + 1 for the patron's home library
8) Note the patron can again place another hold
9) Set the new max holds rule to X for the patron's home library
10) Note the patron can no longer place another hold

Signed-off-by: Lisette Scheer <lisetteslatah@gmail.com>
Signed-off-by: Jesse Maseto <jesse@bywatersolution.com>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>