Adding Tkinter GUI (#677)

* 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

* Added Uniform Cost Search in GUI