feat: add support for custom node qualifier

[gwardwell]

Description

This PR adds support for a custom schema node qualifier so users can use custom logic to determine whether an entity should or should not be included in the node-relay schema based on custom logic.

Type of Change

• [ ] Bug Fix
• [X] New Feature
• [ ] Breaking Change
• [ ] Refactor
• [ ] Documentation
• [ ] Other (please describe)

Checklist

• [X] I have read the contributing guidelines
• [X] Existing issues have been referenced (where applicable)
• [X] I have verified this change is not present in other open pull requests
• [x] Functionality is documented
• [x] All code style checks pass
• [X] New code contribution is covered by automated tests
• [X] All new and existing tests pass

[codecov[bot]]

Codecov Report

Merging #21 (4d707ff) into main (1055e66) will increase coverage by 0.02%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main      #21      +/-   ##
==========================================
+ Coverage   96.81%   96.84%   +0.02%     
==========================================
  Files          17       17              
  Lines         283      285       +2     
  Branches       87       88       +1     
==========================================
+ Hits          274      276       +2     
  Misses          9        9              

Impacted Files	Coverage Δ
src/schema/generateFroidSchema.ts	96.69% <100.00%> (+0.05%)	:arrow_up: