Code Simplifier Step: support the ISimplifierRulesParameters filter parameters to override the step ones

The Wiki page mentions that all filters support code simplification rules. However, the functionality can't be used by Rainbow or Longhorn this way. And the only available step-level rules configuration might not always be feasible.

A solution can be done by processing the start document event and loading filter parameters.

This applies to PostSegmentationCodeSimplifierStep as well.