Make key scopes visible to SQL

[bgaidioz]

This is implemented using a postgres temporary table that is created/cleaned at startup of each query, and filled when scopes are provided. An example query that is then possible:

SELECT
    CASE WHEN 'dev' IN (SELECT * FROM scopes) THEN trip_id END AS trip_id,
    departure_date,
    arrival_date
FROM example.trips

When "dev" is in the scopes:

[
  {
    "trip_id": 0,
    "departure_date": "2016-02-27",
    "arrival_date": "2016-03-06"
  },
  {
    "trip_id": 1,
    "departure_date": "2016-04-10",
    "arrival_date": "2016-04-17"
  },
  {
    "trip_id": 2,
    "departure_date": "2016-05-22",
    "arrival_date": "2016-05-29"
  },
  {
    "trip_id": 3,
    "departure_date": "2023-01-01",
    "arrival_date": "2023-01-01"
  }
]

When it's not:

[
  {
    "trip_id": null,
    "departure_date": "2016-02-27",
    "arrival_date": "2016-03-06"
  },
  {
    "trip_id": null,
    "departure_date": "2016-04-10",
    "arrival_date": "2016-04-17"
  },
  {
    "trip_id": null,
    "departure_date": "2016-05-22",
    "arrival_date": "2016-05-29"
  },
  {
    "trip_id": null,
    "departure_date": "2023-01-01",
    "arrival_date": "2023-01-01"
  }
]

Another one:

SELECT 'DEV' IN (SELECT * FROM scopes) AS isDev,
       'ADMIN' IN (SELECT token FROM scopes) AS isAdmin

when only ADMIN is listed:

[{"isdev":false,"isadmin":true}]

[torcato]

LGTM