Resource Designer - Feature Enablement and Telemetry

## Summary
As a part of rollout of revamped experience of resource designer, the feature will be enabled in a controlled fashion to solicit feedback and address any bugs prior to enabling it on by default.

- [ ] Document telemetry metrics to be captured for the new Resource Explorer experience
- [x] Add feature flag to enable new experience
- [ ] Disable old experience when new is enabled
- [x] Define feature usage telemetry to be captured
- [ ] Add feature usage telemetry to product
- [ ] Data classification

## User Impact
Risk mitigation - stabilization is addressed prior to release.