SAT: Assert that additionalProperties: false is not specified in json schemas

[pedroslopez]

(more context in parent issue #14097)

Following up on #14196, to encode this going forward we should add checks in the SAT to prevent additionalProperties: false.

From the JSON Schema docs, additionalProperties does not necessarily have to be a boolean, so we should just check if it's set and its value is anything other than true.

Acceptance criteria

• A connector spec schema with additionalProperties set to anything other than true fails SAT
• A stream schema with additionalProperties set to anything other than true fails SAT

[pedroslopez]

grooming notes:

• this should also check nested definitions