feat: compile and execute partitioned query

[bjchambers]

The main change here is having the sparrow-execution tests compile from a logical plan, created within a session, and execute things.

Changes Include

• Fix naming field_ref vs. fieldref (matches Python)
• Tweak pipeline scheduling so that only transforms are grouped together.
• Tweak pipelines so that each may output to multiple consumers
• Introduces a SourceTasks so we can poll all inputs on a single tokio task.
• Fixes to how the scheduler detects "completion" (empty queue isn't sufficient).
• Add a "monitor" to detect failing threads ASAP
• Add a "worker idle" so that workers with no tasks sleep.