After SERVER-62251 and SERVER-63630 are completed, ServerParameter and IDLServerParameterWithStorage will be able to store metadata specific to cluster-wide parameters, especially non-specialized ones that have bound storage. This ticket will ensure that these parameters can be defined in IDL, just like node-specific server parameters. It will also ensure and test that specialized cluster server parameters can be implemented using the IDL framework.

1. Expand the set_at field to accept cluster.
2. Update IDL code generator for MONGO_SERVER_PARAMETER_REGISTER blocks so that the generated constructors reflect the changes made in SERVER-63630 to separate cluster-wide server parameters from node-specific parameters upon instantiation.
3. Add override_validate field to the IDL compiler so that the validate() method can be overridden in specialized server parameter classes.
4. Update IDL/ServerParameter tests as necessary