feature request: SchemaRegistry doc as column description in Snowflake

[ivica-k]

Use case:

We have several hundred Kafka topics with AVRO schemas. These topics contain operational data that is ingested into Snowflake by this connector (running on Confluent). AVRO schemas contain field descriptions, and having those descriptions as column descriptions in Snowflake tables would greatly enrich data with metadata.

After several internal discussions, we agreed that the best place for this feature would be on the connector, and a similar feature is already implemented for JSON schemas in #870

I'm sorry these examples are screenshots and not code.

Example AVRO schema:

Example Snowflake table whose column descriptions were set manually: