Add support for adding and subtracting lists and dicts

[ShawnClake]

Adding lists and dicts will merge the contents

Subtracting lists and dicts will remove the keys from the first if they exist in the second.

Allowed types:

• list - list -> [] - []
• dict - dict -> {} - {}
• dict - list -> {} - []
• list + list -> [] + []
• dict + dict -> {} + {}