Simplify functions in preparation for PartiQL-PATH

[RCHowell]

Relevant Issues

#1496

Description

This PR simplifies functions in SPI in preparation for the SQL-PATH. This is being done in conjunction with the PartiQL-Environment where connectors will be implemented on top of the catalog interfaces. This is an intermediate step towards the final state.

Other Information

• Updated Unreleased Section in CHANGELOG: No
• Any backward-incompatible changes? No
• Any new external dependencies? No
• Do your changes comply with the Contributing Guidelines
  and Code Style Guidelines? Yes

License Information

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[github-actions]

Conformance comparison report-Cross Engine

	Base (legacy)	eval	+/-
% Passing	92.51%	94.25%	1.74%
✅ Passing	5434	5537	103
❌ Failing	440	338	-102
🔶 Ignored	0	0	0
Total Tests	5874	5875	1
Number passing in both: 5176

Number failing in both: 79

Number passing in legacy engine but fail in eval engine: 259

Number failing in legacy engine but pass in eval engine: 361
⁉️ CONFORMANCE REPORT REGRESSION DETECTED ⁉️
The complete list can be found in GitHub CI summary, either from Step Summary or in the Artifact.
361 test(s) were failing in legacy but now pass in eval. Before merging, confirm they are intended to pass.
The complete list can be found in GitHub CI summary, either from Step Summary or in the Artifact.

Conformance comparison report-Cross Commit-LEGACY

	Base (26d5fd3)	bda6246	+/-
% Passing	92.51%	92.51%	0.00%
✅ Passing	5434	5434	0
❌ Failing	440	440	0
🔶 Ignored	0	0	0
Total Tests	5874	5874	0
Number passing in both: 5434

Number failing in both: 440

Number passing in Base (26d5fd3) but now fail: 0

Number failing in Base (26d5fd3) but now pass: 0

Conformance comparison report-Cross Commit-EVAL

	Base (26d5fd3)	bda6246	+/-
% Passing	94.25%	94.25%	0.00%
✅ Passing	5537	5537	0
❌ Failing	338	338	0
🔶 Ignored	0	0	0
Total Tests	5875	5875	0
Number passing in both: 5537

Number failing in both: 338

Number passing in Base (26d5fd3) but now fail: 1

Number failing in Base (26d5fd3) but now pass: 1
⁉️ CONFORMANCE REPORT REGRESSION DETECTED ⁉️. The following test(s) were previously passing but now fail:

Click here to see

• Example 6 — Value Coercion, compileOption: LEGACY

The following test(s) were previously failing but now pass. Before merging, confirm they are intended to pass:

Click here to see

• Example 6 — Value Coercion, compileOption: LEGACY

[johnedquinn]

Why ANY?

[johnedquinn]

There are 31 conformance tests now failing -- potentially due to the use of ANY here.

[RCHowell]

I likely just pulled the Fns from an older v1 commit. Let me get the latest definitions.