##### SUMMARY
Can functionality be added so that "Associable Object Types" can be configured for a tag category please?

##### ISSUE TYPE
- Feature Idea

##### COMPONENT NAME
vmware_category

##### ADDITIONAL INFORMATION
Perhaps the module could be extended to include a list, examples below;
```
- name: 'Create a Category'
  connection: 'local'
  vmware_category:
    hostname: '{{ ansible_host }}'
    username: '{{ ansible_vcenter_username }}'
    password: '{{ ansible_vcenter_password }}'
    category_name: "sas_luns"
    category_description: "SAS LUNS"
    category_cardinality: 'multiple'
    associable_object_types:
         - Datastore
         - Datastore Cluster
    state: present
    validate_certs: '{{ validate_certs }}'

- name: 'Create a Category'
  connection: 'local'
  vmware_category:
    hostname: '{{ ansible_host }}'
    username: '{{ ansible_vcenter_username }}'
    password: '{{ ansible_vcenter_password }}'
    category_name: "Region 1"
    category_description: "Region"
    category_cardinality: 'multiple'
    associable_object_types:
         - All objects
    state: present
    validate_certs: '{{ validate_certs }}'
```
The type of Associable Object Types in vSphere 6.7 are:
All objects
Folder
Cluster
Datacenter
Datastore
Datastore Cluster
Distributed Port Group
Distributed Switch
Host
Content Library
Library item
Network
Resource Pool
vApp
Virtual Machine

def __init__(self, module):
        super(VmwareCategory, self).__init__(module)
        self.category_service = self.api_client.tagging.Category
        self.global_categories = dict()
        self.category_name = self.params.get('category_name')
        self.get_all_categories()
    def ensure_state(self):
        """Manage internal states of categories. """
        desired_state = self.params.get('state')
        states = {
            'present': {
                'present': self.state_update_category,
                'absent': self.state_create_category,
            },
            'absent': {
                'present': self.state_delete_category,
                'absent': self.state_unchanged,
            }
        }
        states[desired_state][self.check_category_status()]()
    def state_create_category(self):