Auto reseller: broker car sales

[ybyzek]

Describe the use case
Auto reseller, using ksqlDB to give real-time status on brokered vehicles, pricing, etc

Provide the ksqlDB application

Key functions to use:

• LATEST_BY_OFFSET (to get latest value of car info)
• CASE and SUBSTRING (handling cases)

ksqlDB app example, for Confluent-internal only