test: unit tests fix

[Ayaz-Microsoft]

Purpose

Fixed Azure Blob Storage configuration file mocking in functional tests that was causing JSON decode errors and "Required Content-Range response header is missing or malformed" exceptions
Resolved blob storage HTTP response format issues by changing from [respond_with_json()] to [respond_with_data()] to properly simulate Azure Blob Storage API behavior
Added dynamically calculated Content-Range headers that the Azure Blob Storage SDK requires for successful blob downloads
Updated semantic kernel orchestrator tests to handle the new chat history string format instead of individual message objects
Cleaned up test function signatures by removing unused [app_config] parameters

• ...

Does this introduce a breaking change?

• Yes
• No

How to Test

• Get the code

git clone [repo-address]
cd [repo-name]
git checkout [branch-name]
npm install

• Test the code

What to Check

Verify that the following are valid

• ...

Other Information