Minor: Refactor some sql planning code into functions

[alamb]

Draft as it builds on #4779

Which issue does this PR close?

re #4065

Rationale for this change

I am trying to make the code in sql_expr_to_logical_expr as uniform as possible to avoid reintroducing issues like #4065

What changes are included in this PR?

Extract a few more functions

Are these changes tested?

Existing tests

Are there any user-facing changes?

No

[jackwener]

Nice job to me

[ursabot]

Benchmark runs are scheduled for baseline = ad96d41 and contender = 00a22cb. 00a22cb is a master commit associated with this PR. Results will be available as each benchmark for each run completes.
Conbench compare runs links:
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on ec2-t3-xlarge-us-east-2] ec2-t3-xlarge-us-east-2
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on test-mac-arm] test-mac-arm
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on ursa-i9-9960x] ursa-i9-9960x
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on ursa-thinkcentre-m75q] ursa-thinkcentre-m75q
Buildkite builds:
Supported benchmarks:
ec2-t3-xlarge-us-east-2: Supported benchmark langs: Python, R. Runs only benchmarks with cloud = True
test-mac-arm: Supported benchmark langs: C++, Python, R
ursa-i9-9960x: Supported benchmark langs: Python, R, JavaScript
ursa-thinkcentre-m75q: Supported benchmark langs: C++, Java