Organize v2 context.

- Opinionated but consistent organization and sorting.
- Semantically equivalent to previous style.
- Order is recursive and roughly follows a pattern:
  - JSON-LD keywords
  - blank line
  - id/type terms
  - blank line
  - jose/jwt property terms
    - sorted
  - blank line
  - other property terms
    - sorted
  - blank line
  - type terms
    - sorted
    - for TypeCredential/Type pairs, put TypeCredential first
    - blank line between each
- Drop down and indent values to try and be under 80 chars per line.