Add missing data in streams

[laurentS]

This PR updates 2 streams to use the sdk schema definition format instead of JSON files and:

• projects now includes (optionally) a license object
• issues includes more complete author and assignees objects which were missing

The tap's output did not necessarily match the data returned by the api, so this might seem to break compatibility, but I think the missing fields were null anyway.

[sonarcloud[bot]]

SonarCloud Quality Gate failed.   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
1 Code Smell

No Coverage information
6.3% Duplication

[laurentS]

Closing in favour of #71