Add __init__.py files

[jonathangreen]

Description

Some of our modules were missing __init__.py files to mark the directory as a module. I think this is causing some subtle problems with imports, since that makes these folder namespace packages instead of modules.

Motivation and Context

Make sure we are consistently using __init__.py to mark modules in the package.

How Has This Been Tested?

• Running tests in CI.

Checklist

• I have updated the documentation accordingly.
• All new and existing tests passed.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 90.22%. Comparing base (23b26e3) to head (c644c82).

Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1762   +/-   ##
=======================================
  Coverage   90.22%   90.22%           
=======================================
  Files         247      247           
  Lines       28305    28305           
  Branches     6447     6454    +7     
=======================================
+ Hits        25538    25539    +1     
+ Misses       1830     1829    -1     
  Partials      937      937           

Flag	Coverage Δ
Api	75.81% <ø> (-0.17%)	⬇️
Core	59.42% <ø> (-0.42%)	⬇️
migration	24.09% <ø> (-2.96%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[tdilauro]

🚀

Funny. I don't ever recall running into a problem because of this.