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

• Each feast offline store has to more or less reimplement the same data transformation logic (mainly point-in-time join) in their respective technologies. It's hard to ensure feature parity.
• It's next to impossible to properly incorporate ODFV logic into offline store operations.

Describe the solution you'd like

• Implement abstract offline store with ibis that other feature stores can extend and customize. Ibis is a lightweight python library that offers a universal dataframe API with pluggable query engine backends. As of now it can interface with 15+ engines with varying level of API coverage, including BigQuery, Snowflake, Pyspark, PosgreSQL, Trino and others.
• ibis-based offline stores should be able to turn Substrait-based on demand feature view transformations into ibis expressions and execute them right alongside core offline store logic in one go.