Replace RestSharp For HttpClient

[Martin-Molinero]

Expected Behavior

• We use dotnet runtime httpclient, more efficient and will be kept up to date

Actual Behavior

• We use outdated RestSharp

Potential Solution

• Replace in lean & other repos

Reproducing the Problem

N/A

System Information

N/A

Checklist

• [x] I have completely filled out this template
• [x] I have confirmed that this issue exists on the current master branch
• [x] I have confirmed that this is not a duplicate issue by searching issues

• [x] I have provided detailed steps to reproduce the issue

[MandeepCodes]

@jhonabreul , are you working on this, let me know if you need any help here

[dacrowlah]

I've created comprehensive design documentation for this migration issue.

Draft PR: #9073

Approach: Two-phase abstraction-first migration

• Phase 1: IHttpService abstraction + 85+ comprehensive tests
• Phase 2: Simple implementation swap (RestSharp to HttpClient)

The design documentation covers:

• Complete risk analysis of current state
• Detailed task breakdowns for both phases
• Test infrastructure design (SOLID/DRY principles)
• Success criteria and validation procedures

Looking for feedback on the architectural approach before beginning implementation. All review comments welcome!

[Martin-Molinero]

Hey @dacrowlah! Thanks for looking into it. This is a very core and big change in lean, cross repository. That's why it will be better for the core team to handle it. Suggest looking at issues with the 'good first issue' instead label. If there's any issue causing u to look at this instead please let us know though.