[Gluten-147] Made the needed changes to update Velox

[rui-mo]

What changes were proposed in this pull request?

• Changed the Substrait plan generation logic when an pre-project is needed in aggregation. Unique columns will be selected by pre-projection.
• Supported cast node.
• Updated the docs.

After this change, Gluten will depend on the Velox under oap-project.

Fixed #147.

How was this patch tested?

locally verified

[github-actions]

Thanks for opening a pull request!

Could you open an issue for this pull request on Github Issues?

https://github.com/oap-project/gluten/issues

Then could you also rename commit message and pull request title in the following format?

[Gluten-${ISSUES_ID}] ${detailed message}

See also:

• Other pull requests

[github-actions]

#147

[zzcclp]

LGTM, verified locally with clickhouse backend.