feat(oas-to-har): retain null values in array

[eaglethrost]

🚥 Resolves ISSUE_ID

🧰 Changes

This PR is part of the work for the readme ticket RM-9906 Not displaying null values in an array and should get merged ONLY after the corresponding PR changes in the remove-undefined-objects repo is shipped

The aim of the ticket is we want user-added null values in arrays to be visible in requests.

This requires adjustments in the oas-to-har package, with two separate causes of why the nulls in array are being dropped

1. For postData (body):

• Issue: remove-undefined-objects was filtering out null values in arrays.
• Fix: Replaced JSON.parse/stringify approach with a custom function to distinguish actual null vs. undefined.
  Updated stripEmptyObjects to stop removing null values in arrays, while still removing undefined, empty objects, and empty arrays.

2. For Non-postData (parameters, cookies, etc.):

• Issue: encodeArray in style-serializer used .join, which dropped null values.
• Fix: Convert null values to the string "null" before joining, so they’re preserved.

TODO Before Merging:

• Update the remove-undefined-object package version once this PR is shipped: refactor: retain null values in array remove-undefined-objects#149

🧬 QA & Testing

• Temporarily migrated tests for remove-undefined-objects to show the changes works
• Run oasToHar or oasToSnippet in a script with an OAS object containing arrays of null, undefined, and undefined objects

[erunion]

why are we vendoring and forking remove-undefined-objects in here instead of adding a new option to that library for preserving empty arrays? thats what @mjcuva and i talked about out what i thought needed to happen for this ticket

[eaglethrost]

Sorry this PR is not for that ticket, but a different one, which tries to solve a different issue of null values in arrays getting dropped in the request snippet.

The PR's related to the ticket you were referring to are these:

• feat: add preserve empty array option remove-undefined-objects#148
• feat(oas-to-har): add check to preserve empty arrays #999

[kanadgupta]

can you use the latest release of remove-undefined-objects@7.0.0 here?