Implement feature with associated test cases

[developernajib]

Issues Identified:

1. After sending a message, if the system is slow, there is a delay in response, but no processing message is displayed.
2. There is no "Stop" button available to terminate the current message.

Fixes Implemented:

1. An initial processing message has been added to indicate system activity.
2. A "Stop" button has been implemented to allow users to terminate the current request.
3. A loading spinner has been added to visually indicate download progress.

Request Processing

Terminate Request