Add TypeSystem.extends

[JamesOswald]

Description

Fixes #243

Type of change

• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)

How Has This Been Tested?

Added test_TypeSystem_extends.

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in upstream modules

[JacobHayes]

I need to figure out how to handle unresolved ForwardRefs (extends here) in the runtime type checking logic. Pydantic resolves the field's type_ attribute, but not outer_type_.

[JacobHayes]

FYI: I created pydantic/pydantic#4249 to fix the unresolved ForwardRefs on field.outer_type_, but will likely work around it in another arti PR 3a0d41e to unblock sooner.

[JacobHayes]

Looks great, thanks for working on this! I'm excited to use this very soon for the numpy->pandas type systems!

[JacobHayes]

FYI: I added this to fix the "runtime type checking" done on inputs to our Models.

[codecov-commenter]

Codecov Report

Merging #250 (3fd17b6) into golden (73a9107) will not change coverage.
The diff coverage is 100.00%.

@@            Coverage Diff            @@
##            golden      #250   +/-   ##
=========================================
  Coverage   100.00%   100.00%           
=========================================
  Files           39        39           
  Lines         2450      2448    -2     
  Branches       512       513    +1     
=========================================
- Hits          2450      2448    -2     

Impacted Files	Coverage Δ
src/arti/types/__init__.py	100.00% <100.00%> (ø)
src/arti/types/pyarrow.py	100.00% <100.00%> (ø)
src/arti/types/pydantic.py	100.00% <100.00%> (ø)
src/arti/types/python.py	100.00% <100.00%> (ø)

📣 Codecov can now indicate which changes are the most critical in Pull Requests. Learn more