Non-data fields - Metadata fields to Kafka Connector

[vaibhawvipul]

enabling users to query using the following syntax -

create table users (
    id TEXT,
    name TEXT,
    offset BIGINT GENERATED ALWAYS AS (metadata('offset_id')) STORED
) with (
    connector = 'kafka',
    ...
);

Demo -

[vaibhawvipul]

@mwylde can you please trigger the CI again? I am asking because my last commit ran successfully, the failed CI is on master merge.