refactor: decouple demos from searching_algorithms

[saitejasviputta]

Summary

This PR refactors the searching_algorithms module by moving the interactive demo implementations out of the algorithm source files into a dedicated demos/searching_algorithms/ directory.

The algorithm implementation files now contain only the search algorithm logic, while the interactive console demos are separated into their own files.

Changes Made

• Created a new demos/searching_algorithms/ directory.
• Moved interactive *_demo() functions from src/searching_algorithms/ into separate demo source files.
• Updated the build system (Makefile and CMakeLists.txt) to include the new demo directory.
• Added/updated required function declarations where necessary after separating demo code.
• Preserved all existing functionality without changing algorithm behavior.

Testing

• Built the project successfully using make.
• Verified the application launches correctly using make run.

Closes #860