Develop tests and document '/api/groups/group_info/'

[Reeya123]

Documentation needs to be updated. Add an example case

[Reeya123]

Expected response codes for endpoint api/groups/group_info/ on Swagger documentation:

After testing, expected response: 200 (Authorization is successful) received response: 200 (Authorization is successful)

**expected response: 400 (Bad request) received response: 403 (Forbidden Request)

expected response: 401 (Unauthorized: Authentication credentials were not valid) received response: 403 (Forbidden Request)**

Update Swagger documentation