feat(masfeat): add MAS FEAT compliance namespace

Add MASFEATNamespace inner class with all MAS FEAT API methods:

Registry:
- registerSystem, activateSystem, getSystem, getRegistrySummary

Assessments:
- createAssessment, getAssessment, updateAssessment
- submitAssessment, approveAssessment, rejectAssessment

Kill Switch:
- getKillSwitch, configureKillSwitch, triggerKillSwitch
- restoreKillSwitch, getKillSwitchHistory

Includes field name mapping (customerImpact → risk_rating_impact, etc.)
and response parsing with alternate field name handling.

Author: saurabhjain1592