Add support to add headers to Kafka Sink

[mbombonato]

Is your feature request related to a problem? Please describe.

No

Describe the solution you'd like

CREATE SINK kafka_sink AS SELECT
   "user_id", "user_name", "tenant_id"
FROM my_view
WITH (
    connector='kafka',
    properties.bootstrap.server = 'localhost:9092',
    topic='topic',
    primary_key='user_id,tenant_id',
    headers='X-Tenant-Id: tenant_id, X-User-Id: user_id',
    allow.auto.create.topics='true'
)
FORMAT UPSERT ENCODE JSON;

Describe alternatives you've considered

No response

Additional context

I'd also add the possibility to map a jsonb field to it. Like:
"X-User-Id: user.id"

(That would also be great for the primary-key)

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[mbombonato]

This is still relevant. The "Additional Context" is also relevant.