Fix: Handle Request objects in Segment fetch override

[amirtds]

Change description

This change fixes the TypeError that was thrown when trying to call substr on a Request object and ensures that analytics events are correctly replicated to the appropriate Segment backends.

Type of change

• Bug fix (fixes an issue)
• New feature (adds functionality)

Related issues

https://appsembler.atlassian.net/browse/ENG-334

Checklists

Development

• Lint rules pass locally
• Application changes have been tested thoroughly
• Automated tests covering modified code pass

Security

• Security impact of change has been considered
• Code follows company security practices and guidelines

Code review

• Pull request has a descriptive title and context useful to a reviewer. Screenshots or screencasts are attached as necessary
• "Ready for review" label attached and reviewers assigned
• Changes have been reviewed by at least one other contributor
• Pull request linked to task tracker where applicable

[bryanlandia]

I think it looks good but let's test the Segment case on staging before pushing to prod

[github-actions]

Checking git merge conflicts against https://github.com/edx/edx-platform.git

Comparing with	open-release/nutmeg.master
Benchmark conflicts with main	299
Current conflicts	299
Summary	Good work! No added conflicts.

Comparing with	master
Benchmark conflicts with main	320
Current conflicts	320
Summary	Good work! No added conflicts.