Simplifies logical model of the path expression

[johnedquinn]

Relevant Issues

• In Modifies how we model paths in the plan #1271, I mentioned the desire to move the typing of paths to the AST transformation. This PR does not do that exactly, however, it resolves the underlying issue.

Description

• As part of the effort to model our logical plan as closely to the underlying data flow as possible, this PR models path expressions in a more representative manner. Specifically, a Path, in this PR, is a single step on some root. Therefore, we can directly compile logical plan nodes into physical plan nodes that represent the underlying operation (i.e. index lookup, sensitive lookup, insensitive lookup).
• To do this, upon transforming the AST to a Logical Plan (Unresolved), we take the ExprPath and attempt to grab the first steps to make a qualified identifier (Var Unresolved). This subtle change gives us the ability to attempt to resolve the qualified identifier in the planner without needing to maintain the syntactic metadata in the logical unresolved plan. See Modifies how we model paths in the plan #1271
• While resolving a qualified identifier, it may actually be that a subset of the identifier is a Global/Local. In that case, we use the remaining steps to construct a path. And, once we have a path, it's quite easy to type, since we model each path step as its own expression operator.
• Tests are unchanged (except when necessary for API changes).

Other Information

• Updated Unreleased Section in CHANGELOG: NO
• Any backward-incompatible changes? NO -- 0.14.0 hasn't been released yet
• 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 (c7c7972)	50f5fed	+/-
% Passing	92.54%	92.54%	0.00%
✅ Passing	5384	5384	0
❌ Failing	434	434	0
🔶 Ignored	0	0	0
Total Tests	5818	5818	0

Number passing in both: 5384

Number failing in both: 434

Number passing in Base (c7c7972) but now fail: 0

Number failing in Base (c7c7972) but now pass: 0

[codecov-commenter]

Codecov Report

All modified and coverable lines are covered by tests ✅

Comparison is base (c489057) 72.16% compared to head (fee1474) 72.16%.
Report is 9 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff            @@
##               main    #1306   +/-   ##
=========================================
  Coverage     72.16%   72.16%           
  Complexity     2097     2097           
=========================================
  Files           221      221           
  Lines         15974    15974           
  Branches       2892     2892           
=========================================
  Hits          11528    11528           
  Misses         3640     3640           
  Partials        806      806           

Flag	Coverage Δ
CLI	11.86% <ø> (ø)
EXAMPLES	80.28% <ø> (ø)
LANG	80.80% <ø> (ø)

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