Python: Fix schema building for complex types

[moonbox3]

Motivation and Context

The schema building for complex types worked in some regard, but it didn't work for all cases. There needs to be better checks on complex types, if they have args and if so, recurse to the base class type, and also grab the type that is specified in the list like list[CustomClass], list[str] or even Union[int, bool].

Description

This PR improves the parsing/building of complex types. Added integration tests to cover more types in the hope that this doesn't lead to any more issues.

• Closes Python: In v1.0.2 it's not possible to have lists or dictionaries as fields of a KernelBaseModel #6388

Contribution Checklist

• The code builds clean without any errors or warnings
• The PR follows the SK Contribution Guidelines and the pre-submission formatting script raises no violations
• All unit tests pass, and I have added new tests where possible
• I didn't break anyone 😄

[markwallace-microsoft]

Python 3.10 Test Coverage Report •

File	Stmts	Miss	Cover	Missing
TOTAL	6096	879	86%

report-only-changed-files is enabled. No files were changed during this commit :)

Python 3.10 Unit Test Overview

Tests	Skipped	Failures	Errors	Time
1374	1 💤	0 ❌	0 🔥	15.974s ⏱️

[eavanvalkenburg]

Mostly testing, but forward refs vs regular definition can be a pain to deal with!

[eavanvalkenburg]

LGTM