Add Management API calls for session API endpoints

[l15n]

Changes

Add support for the Session resource endpoints in the Management API.

References

These endpoints are described in https://auth0.com/docs/manage-users/sessions/manage-user-sessions-with-auth0-management-api#session-resource

Description	Request	Grants
Introspect a specific session by ID	GET /api/v2/sessions/{sessionId}	read:sessions
Delete a specific session by ID	DELETE /api/v2/sessions/{sessionId}	delete:sessions

The user session endpoints were previously added in #588

Testing

Please describe how this can be tested by reviewers. Be specific about anything not tested and reasons why. If this library has unit and/or integration testing, tests should be added for new functionality and existing tests should complete without errors.

• This change adds unit test coverage
• This change adds integration test coverage
• This change has been tested on the latest version of Ruby

Checklist

• I have read the Auth0 general contribution guidelines
• I have read the Auth0 Code of Conduct
• All existing and new tests complete without errors
• Rubocop passes on all added/modified files
• All active GitHub checks have passed

[l15n]

Rubocop passes on all added/modified files

To clarify, Metrics/BlockLength is triggered on spec/lib/auth0/api/v2/sessions_spec.rb because the describe block is longer than 25 lines. This rule is unrealistic for rspec, and (almost?) all other spec files trigger the offense as well.