lab3 create command shape list

[z-huu]

when creating a shape, we need to check that the passed type adheres to these requirements

as in the passed type is either a ellipse, circle, rectangle, or triangle

should they pass a type that is not allowed, the following err msg should be displayed

[z-huu]

implemented helper function to check after we take in type as an argument, shown here

the helper function is not efficient but makes use of a globally defined array. the function implementation is shown here