feat: vendor datafusion-cli helpers for parity

[lidavidm]

Vendor code from datafusion-cli that implements various conveniences like being able to select directly from a URI. Also do a bit of internal code cleanup to reduce duplication (I noticed the LLM kept getting confused as heck as it kept only adding things to one path instead of all of them).

Assisted-by: Claude Opus 4.6 noreply@anthropic.com

[ianmcook]

I downloaded the .dylib from the CI artifacts, installed it locally, and ran a variety of the queries from the DataFusion CLI user guide. Everything seemed to work great.

[ianmcook]

In the docs, how about linking to the DataFusion CLI docs, and using one of the examples there, e.g.

SELECT COUNT(*) FROM 'https://datasets.clickhouse.com/hits_compatible/athena_partitioned/hits_1.parquet';

[ianmcook]

Or here's a fun publicly hosted one from https://github.com/hyparam/hyparquet:

SELECT `Breed Name`, `Lifespan`
  FROM 'https://hyperparam-public.s3.amazonaws.com/bunnies.parquet'
  ORDER BY `Lifespan` DESC
  LIMIT 5;