Added a CommandWithTerm Class

Added new CommandWithTerm Class similar to the CommandWithMeta Class.
Designed to reusable for different object types. Currently this is draft and I am still testing it. Just wonder if I was on the right track with this solution. Feedback is requested. I will write tests when I know that I am on the right track. 

Related #1379
How would ```wp post term taxonomies ``` work for custom post types or any other object type? The use case I am discussing is a custom post type with custom taxes on it. The user will not know the tax name as it is not built in and they may not have registered them. What you suggest removes functionality and makes it hard for users to get information. If all you want is just every term linked to an object, it adds more work for the user. I don't understand why is unclear about it. Consistencies is not a good reason to remove functionality, even it is different, it is better user interaction. 

Daisy chaining commands means nested commands like this.
```wp post delete $(wp post list --post_type='page' --format=ids)```

To if you wanted to do what the current functionality you would have to do something like this. 

```wp post term $(wp term taxonomies --fields=name) 123```
Above is just a pain to do and most users will not bother.