Fix: Resolve redundant callbacks and missing payloads in HttpRequest

[lavjeetrai]

Summary
Refactors the legacy HttpRequest constructor to use onload and onerror instead of onreadystatechange. This prevents callbacks from firing multiple times per request and fixes a bug where userCallback was ignored on success.

Eliminates wasteful, redundant executions of loadCallback (which previously fired on ready states 1, 2, 3, and 4) and ensures successful network payloads are actually passed back to the requesting function.

Category

• Bug Fix

[github-actions]

🧪 Jest Test Results

❌ Some Jest tests failed. Please check the logs and fix the issues before merging.

Coverage: Statements: 48.29% | Branches: 39.89% | Functions: 53% | Lines: 48.69%
Master Coverage: Statements: 48.3% | Branches: 39.91% | Functions: 53.01% | Lines: 48.7%

Note: These failures may be introduced by this PR or may already exist in the master branch.
Tip: Update your branch with the latest master and rerun tests.
If the same failures are present on master, they are likely not introduced by this PR.

Failed Tests:

aidebugger.test.js

[lavjeetrai]

The aidebugger.test.js failure is an existing issue currently failing on master. I verified this locally—it is completely unrelated to my changes.

[lavjeetrai]

@Ashutoshx7 can u reveiw this pr when u have time ?

[lavjeetrai]

@walterbender can u have a loook to these changess when got time ?