Add navigation for security requirement scopes

[ghillairet]

In case the security scheme is oauth or openIdConnect, it should be doable to provide navigation to the named scopes.

For ex, clicking on write:pets

petstore_auth:
- write:pets
- read:pets

would move the cursor to the scope write:pets in /definitions/securitySchemes:

type: oauth2
flows: 
  implicit:
    authorizationUrl: https://example.com/api/oauth/dialog
    scopes:
      write:pets: modify pets in your account
      read:pets: read your pets

Related to #335