RDDL fixes and improvements

[gerardcanal]

It includes different fixes:

• CMake flags for rddl parser
• Added some services to get type of fluents (including enumerable types)
• Removed ippc2018 flag for rddl parser in RDDLTaskParser line 35 which may cause some endless loop when parsing some domains
• Fixed RDDLSIMPlannerInterface
• Fixed RDDLProblemGenerator with enum types
• Fixed some typos

[m312z]

I wonder what kind of relation enumerable types might have to constants, and what would be required to have an interface that adapts the RDDL KB to PDDL and vice versa.

[m312z]

As another comment, a service that fetches the type of an object instance could also be added to the PDDL KB, as noted in issue #203. Is it possible that they share message types? If so, then that future PR could change the file and variable names.