[product-catalog] use database for products

[puckpuck]

Changes

• Adds a postgres DB schema for the product catalog.
• The product catalog service will make a database query on each request (List, Get, Search). No more local cache for the product catalog that gets refereshed every 10 seconds
• All database calls are instrumented using XSAM/otelsql with recent semantic conventions applied
• Updates the Postgres Docker deployment to use the official Postgres image with a mounted volume for the init db, instead of building an image with this file for the demo. We can use a configmap to achieve similar in Helm/K8s.

Merge Requirements

For new features contributions, please make sure you have completed the following
essential items:

• CHANGELOG.md updated to document new feature additions
• Appropriate documentation updates in the [docs][]
• Appropriate Helm chart updates in the [helm-charts][]