Math Expression Evaluator for VBA

The VBAexpressions class serves as an intermediary between user interfaces and the main VBA/custom functions exposed through it. The main objective of the development of the class is to demonstrate that all mathematical expressions can be evaluated computationally using an approach similar to the one we humans use: divide the function into sub-expressions, create a symbolic string (lambda) to draw the evaluation flow of the expression, split the sub-expressions into chunks of operations (tokens) by tokenization, evaluate all the tokens.