FakeConsumer consume does not match confluent kafka API

[markjbyrne]

Describe the bug

The consume function of the FakeConsumer class returns either a Message or None. This doesn't meet the confluent-kafka spec which lists the return type as list([Message])

Expected behavior
list(Message) is returned

[alm0ra]

@markjbyrne, thank you for bringing up this issue.

As discussed in #65, we had initially envisioned simplifying the project, which led to the inability to consume multiple messages without committing them.

By resolving this issue, we'll also address the current concern.

Additionally, we have now implemented a consume method that functions similarly to .poll() methods and returns just one message.

[alm0ra]

issue fixed in v0.1.55