Execute Calcite PPL query in thread pool

[LantaoJin]

Description

Execute Calcite PPL query in thread pool

Related Issues

Resolves #3507

Check List

• New functionality includes testing.
• New functionality has been documented.
• New functionality has javadoc added.
• New functionality has a user manual doc added.
• API changes companion pull request created.
• Commits are signed per the DCO using --signoff.
• Public documentation issue/PR created.

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[dai-chen]

Just wonder calcite planner is also required to run in worker thread?

[dai-chen]

Please double check the CI failure. Thanks!

[LantaoJin]

Just wonder calcite planner is also required to run in worker thread?

Calcite planner is generated per query. So it should be safe in thread pool.

PS: I found this change is useless. Below code should be equivalent after #792 @dai-chen

public void execute() {
  client.schedule(
    () ->
       {body});
}

public void execute() {
 body
}

Merge this PR to keep code style consistent.