Vectorizer tests target the lambda handler and not the CLI

[alejandrodnm]

We ported the vectorizer code from an internal repository, that tested against the lambda_handler. The tests and the lambda handler were ported as is, this enabled us to move everything without causing errors on the tests.

The way the vectorizer is exposed is via the vectorizer script and the Worker, Vectorizer classes. We need to update the tests, and decide what to do with the lambda handler.

We can move it to an examples section for vectorizer, or update the code and expose the lambda handler for people to use it.