Is your feature request related to a problem? Please describe.
Feast should allow for use of just the APIs that talk to online/offline stores without having to use all the Feast constructs like data sources and feature views in order to support use cases that utilize other non-Feast tooling for data frame population.

e.g. User has pipelines that handle getting the data into data frames already and just wants an optimized way to write and read from storage without writing the connections from scratch.

Describe the solution you'd like
API access to offline/online without Feast abstractions