add wrapping crate springql

[kazuk]

Motivation

Our project main crate currently named springql-core.

This crate should be run on a small machine such as an in-vehicle microcontroller.

For this reason, I don't want to include anything other than run-time features in springql-core as much as possible.

However, having springql-core with only limited functionality makes it difficult to develop and test.

Adding a springql crate allows for refactoring to move to springql any features that are currently included in springql-core that are not needed at run time.

Refactoring target

add springql crate, simply wrapping splingql-core.