URL check return type: list instead of a single item

[bazi]

Issue

URL being checked can be listed in more than one threat list. Hence, it makes sense for check method to return a list instead of a single item.

Related discussion here in a Google Safe Browsing API mailing list.

Current state

Lookup API uses the first match of the URL in the response.
Update API considers all matches and selects one with more generic effect based on platform type.