Requesting disclosure of 'requested' credentials only returns the latest one even if there are multiple with the same key

[mi-xu]

Steps to reproduce:

• uPort mobile app holds multiple credentials with the same key (ex: nickname: 'bob', nickname: 'rob')
• App calls connect.requestDisclosure({ requested: ['nickname'] })
• uPort mobile app receives disclosure request and prompts user to accept or decline (first part of the issue is that the prompt does not display values for the requested attribute)
• User discloses credentials, but disclosed credentials only contain a single value of the latest credential for each key

Success criteria:

• Disclosure request prompt on the mobile app displays some indication of the available data for each attribute
  • Requesting the same attributes using 'verified' instead of 'requested' will list the issuer of each credential with that key
  • Listing each value may work for simple data types, but what about complex objects?
• Response should contain an array of all credentials that match the 'requested' key if there are multiple

Other considerations:

• What should be the correct behavior when there are credentials with the same key as local profile attributes like 'name' and 'email'?
• Finer control by the user over which credentials get disclosed to fulfill a request needs to be implemented as a separate feature in the near future