deleteTag(store, tag) deletes the specified
    tag.
    Parameters
- store
- A store reference string designating the store in which the tag is located.
- tag
- A string designating the tag to delete.
Returns
void
Example
    if(taggingService.getTag("workspace://SpacesStore", "cloud")){
        taggingService.deleteTag("workspace://SpacesStore", "cloud");
        model.message1 = "Tag successfully deleted!";
    }
    else {
        model.message1 = "Tag does not exist!";
    }
    // ensure deleted
    if(taggingService.getTag("workspace://SpacesStore", "cloud")){
        model.message2 = "Tag found!";
    }
    else {
        model.message2 = "Tag does not exist!";
    }
        
      
      The preceding code snippet would result in the following messages if the tag was found and deleted:
Message1: Tag successfully deleted!
Message2: Tag does not exist!        
        
    