DefaultGenerators returns the set of default generators for use in Factory instances.

HandleResourceRequirementsV1 parses the limits and requests parameters if specified and returns ResourceRequirements.

TODO(sig-cli): Enforce consistent naming for generators here.

GeneratorFn gives a way to easily override the function for unit testing if needed.

The only difference between ServiceGeneratorV1 and V2 is that the service port is named "default" in V1, while it is left unnamed in V2.