Function to create activation key and few tests

What's done in this PR:
- Added a `create` function for now;
  - Create function with create the activation key by passing name, description and can also select the content_view from selection_list
- Implemented tests are:
  - test_positive_create_activation_key_1: `Create Activation key for all variations of Activation key name`
  - test_positive_create_activation_key_2: `Create Activation key for all variations of Description`
  - test_positive_create_activation_key_6: `Create Activation key with default Usage limit (Unlimited)`
  - test_positive_create_activation_key_8: `Create Activation key with minimal input parameters`