Clarify how to handle ICD's V code

[samsontu]

The ICD V codes consist of 3 parts: questions from 2 function-related questionnaires and selected functions from ICF. An integrated Foundation affords us the opportunity to rethink how ICD and ICF should be presented. The current V codes may not be the best way to surface functional assessment in ICD. For example, if we formalize codable categories in ICF, maybe its better to include selected ICF codable categories in ICD instead of placing WHODAS and WHO Model Disability Survey questions in a special ICD chapter. Alternatively, if we want to, we can include in the Foundation the modeling of observable entities in the Foundation. They would be a new subtype of codable category.

[samsontu]

In the initial version of the harmonized Content Model, classify the V codes as belonging to the "Special Category." Entities in the Special Category play no role in the rest of model.