Update CAMARA Mobile Device Identifier API.yaml

[eric-murray]

What type of PR is this?

Add one of the following kinds:

• enhancement/feature

What this PR does / why we need it:

• Separates API into two endpoints:
  • retrieve-identifier to obtain individual device details
  • retrieve-type to obtain type of device
• Add scopes for each endpoint
• Add lastChecked field to indicate when information about device was last confirmed correct

Which issue(s) this PR fixes:

Fixes #47, Fixes #30

Special notes for reviewers:

None

Changelog input

 release-note
 - Separates API into two endpoints:
   - `retrieve-identifier` to obtain individual device details
   - `retrieve-type` to obtain type of device
 - Add scopes for each endpoint
 - Add `lastChecked` field to indicate when information about device was last confirmed correct

Additional documentation

N/A

[eric-murray]

Thanks @Kevsy. Updated.

I also added the text explaining that the phoneNumber will be treated as the secondary MSISDN for scenarios where the primary MSISDN is shared between multiple devices.