Adding Tkinter GUI (2) and Visualization in notebook (#670)

* tic-tac-toe gui added

* Added GUI for Searching

* Added Legend and Minor Fix

* Minor Fix and Options added

* Added Breadth-First Tree Search

* Added Depth-First Tree Search

* Minor Fix

* Added Depth-First Graph Search

* Minor Fix

* Breadth-First Search and Minor Fix

* Added Depth-First Graph Search in notebook

* Added Depth-First Tree Search in notebook

* Cell Placement