chore: return types on module, included-files, and helpers to standardize our typing

[cmwylie19]

Description

Return types on module, included-files, and helpers to standardize our typing

Related Issue

Fixes #1548

Relates to #

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Other (security config, docs update, etc)

Checklist before merging

• Unit, Journey, E2E Tests, docs, adr added or updated as needed
• Contributor Guide Steps followed

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 80.28%. Comparing base (2829066) to head (c0843ee).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1574   +/-   ##
=======================================
  Coverage   80.28%   80.28%           
=======================================
  Files          41       41           
  Lines        1902     1902           
  Branches      445      444    -1     
=======================================
  Hits         1527     1527           
  Misses        346      346           
  Partials       29       29           

Files with missing lines	Coverage Δ
src/lib/helpers.ts	97.93% <100.00%> (ø)
src/lib/included-files.ts	100.00% <100.00%> (ø)
src/lib/module.ts	81.25% <100.00%> (ø)