ARROW-11723: [Rust][DataFusion] Change SQL parser to use PostgreSQL dialect

[Dandandan]

As suggested by @andygrove we should use the PostgreSQL dialect now (by default), now that we decided o be PostgreSQL-compatible.

Currently this makes the VarProvider fail (introduced here: #8135), which depends on identifiers starting with @, and which is not supported in PostgreSQL. I am wondering if we should remove this feature or make it work in another way?

[github-actions]

Thanks for opening a pull request!

Could you open an issue for this pull request on JIRA?
https://issues.apache.org/jira/browse/ARROW

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

ARROW-${JIRA_ID}: [${COMPONENT}] ${SUMMARY}

See also:

• Other pull requests
• Contribution Guidelines - How to contribute patches

[github-actions]

https://issues.apache.org/jira/browse/ARROW-11723

[andygrove]

It would be worth updating the README or other documentation as well

[alamb]

The Apache Arrow Rust community is moving the Rust implementation into its own dedicated github repositories arrow-rs and arrow-datafusion. It is likely we will not merge this PR into this repository

Please see the mailing-list thread for more details

We expect the process to take a few days and will follow up with a migration plan for the in-flight PRs.

[alamb]

#10096 has removed the arrow implementation from this repository (it now resides in https://github.com/apache/arrow-rs and https://github.com/apache/arrow-datafusion) in the hopes of streamlining the development process

Please re-target this PR (let us know if you need help doing so) to one/both of the new repositories.

Thank you for understanding and helping to make arrow-rs and datafusion better