Adds an item to the Labels properties.
This method adds an item to the Label* properties. Name specifies the name of the item, and Value specifies the value of the item.
A resource may have up to 64 labels. Label names and values must consist solely of lowercase letters, numbers, underscores, and hyphens; and may be up to 63 characters in length. Label names must also be unique and begin with a lowercase letter.