Fixes pathing of expressions

[johnedquinn]

Relevant Issues

• None

Description

• Fixes pathing of expressions by visiting root.
• Adds tests for pathing
• Previously, queries would fail because we would forget to type the root of paths (unless the rex was a variable). The following used to fail:
  • [0, 1, 2, 3][0]
  • SELECT typical_allergies[0] AS main_allergy FROM dogs
  • and more
• While this PR doesn't have anything to do with scalar functions, I was previously adding tests for scalar functions and am including them here. See testScalarFunctions in the schema inference tests.

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

	Base (234ff97)	39754d4	+/-
% Passing	92.33%	92.33%	0.00%
✅ Passing	5372	5372	0
❌ Failing	446	446	0
🔶 Ignored	0	0	0
Total Tests	5818	5818	0

Number passing in both: 5372

Number failing in both: 446

Number passing in Base (234ff97) but now fail: 0

Number failing in Base (234ff97) but now pass: 0