[ODG] Use getODSOperands() and getODSResults() to back accessors

[ODG] Use getODSOperands() and getODSResults() to back accessors

This CL added getODSOperands() and getODSResults() as fallback getter methods for
getting all the dynamic values corresponding to a static operand/result (which
can be variadic). It should provide a uniform way of calculating the value ranges.
All named getter methods are layered on top of these methods now.

PiperOrigin-RevId: 252284270