Create rego code for MEET 6.1 and MEET 6.2

[buidav]

💡 Summary

GWS.MEET.6.x Policy groups was added in #570
This issue is to create the corresponding rego code as it looks like we never made an issue? Close as duplicate if there already is.

Implementation notes

• Can this be checked by the policy API?
• If yes then update the mapping in policy_api.py
• Add rego code to MEET.6.1 and MEET.6.2 in meet.rego
• Write unit tests for rego code.

[adhilto]

Not currently supported by the policy API. High priority: add "not implemented" placeholders in the Rego. No need to add the log based checks because API support should be coming soon.