doc: Add an API contract for impersonation session feature

[Suvidh-kaushik]

Issue Description

Create an API contract for PATCH /impersonation/:id which is used for fetching impersonation requests.

Expected Behavior

There will be a new folder for the API contracts of /impersonation route which will contain the contract for PATCH/impersonation/:id

Reproducibility

• This issue is reproducible
• This issue is not reproducible

Severity/Priority

• Critical
• High
• Medium
• Low

Additional Information

• This PR will have the contract for the update impersonation requests feature PR

Checklist

• I have read and followed the project's code of conduct.
• I have searched for similar issues before creating this one.
• I have provided all the necessary information to understand and reproduce the issue.
• I am willing to contribute to the resolution of this issue.