Get databaseId for organizations

[ericboucher]

Following up on #112, we should:

• create a utility function to avoid duplication between repos and users streams
• use this util to implement a similar behavior for organizations and their children's streams

Some initial thoughts on refactoring

Technically, user{i} could be item{i} and we could extract the TempStream as a ContextStream to be shared between users, repos, and orgs streams

Some pseudo code of what I am thinking about:

ContextStream(request_records, request_body) -> [request_body_reponses]

repo:
request_records = [{repo, org}]
request_body = "{nameWithOwner, databaseId, id: nodeId }"

users
request_records = [{login}]
request_body = "{login, databaseId, id: nodeId }"

[laurentS]

#117 is related, and actually makes this refactoring a bit harder because of limitations in the github API.

[ericboucher]

Quick note/heads up, we also need to differentiate Bots. The current implementation does not work if a bot is specified in the list of user_usernames