Add dynamic task config based on DataFusion extension options

[gabotechs]

Enhances the way we configure the network_coalesce_tasks and network_shuffle_tasks parameters. Rather than having these parameters as part of the DistributedPhysicalOptimizerRule, they are now it's own structure that implements ConfigExtension, the standard DataFusion way of passing configuration.

This allows us to ship two main enhancements:

• Now, both parameters can be set in SQL statements as any other parameters, for example:

SET distributed.network_coalesce_tasks = 2;
SET distributed.network_shuffle_tasks = 4;

SELECT ...

• Now, upon setting them programatically, a dynamic number that depends on the the underlaying plan can be specified:

        let state = SessionStateBuilder::new()
            .with_default_features()
            .with_physical_optimizer_rule(Arc::new(DistributedPhysicalOptimizerRule))
            .with_distributed_network_coalesce_tasks(|plan: &Arc<dyn ExecutionPlan>| {
                if plan.as_any().is::<Something>() {
                    1
                } else {
                    4
                }
            })
            .build();

[NGA-TRAN]

Nice.
I only have minor questions to remind myself

[gabotechs]

I'm finding this API a bit annoying to work with in the end...