create code set definitions for CCDH fields

[jiaola]

• NCIt should be (mostly) automatic. ICD-O requires some reverse engineering
• Address missing value reasons
• Address Y/N, Staging and the like

[mellybelly]

please assign @nicolevasilevsky for any mapping curation needed, we also need to chat with Michael Baudis about the status of their ICD-O mappings

[nicolevasilevsky]

@mellybelly should we schedule a meeting with Michael Baudis?