##### 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

results['msg'] = 'Category %s updated.' % self.category_name
            change_list.append(True)
        if any(change_list):
            try:
                self.category_service.update(category_id, category_update_spec)
                changed = True
            except Error as error:
                self.module.fail_json(msg="%s" % self.get_error_message(error))
        self.module.exit_json(changed=changed,
                              category_results=results)
    def state_delete_category(self):
        """Delete category."""
        category_id = self.global_categories[self.category_name]['category_id']
        try:
            self.category_service.delete(category_id=category_id)
        except Error as error:
            self.module.fail_json(msg="%s" % self.get_error_message(error))
        self.module.exit_json(changed=True,
                              category_results=dict(msg="Category '%s' deleted." % self.category_name,
                                                    category_id=category_id))
    def check_category_status(self):
        """
        Check if category exists or not
        Returns: 'present' if category found, else 'absent'
        """
        if self.category_name in self.global_categories:
            return 'present'
        else:
            return 'absent'
    def get_all_categories(self):