Feature Request: Add functions for Stateful Rule Group Management

[iret-m-murakami]

The current rule group functions for Secure do not support stateful rule groups.
To provide full coverage and allow users to manage all types of runtime policies, please consider adding new functions (e.g., get_stateful_rule_group) that specifically target the Stateful Rules Group API endpoint:
api/policies/v3/statefulRules/groups