* Replacing CalculatorVector usage with std::vector
Assumptions made here are that memory allocations
are not recoverable. If it can be proved that an index
will be in range, then the indexing operation is used.
If not (without manual checks) the std::vector::at function
is used to throw an exception in case of a programmer bug.
* Changes based on PR feedback
Using auto& in CalculatorCollector::UpdateHistoryExpression
so the token.first value is properly updated.
Using range for loop to GenerateExpressions.
Setting isEditable directly to the result of boolean expression.
Using token.second directly instead of creating a
separate tokenCommandIndex variable.
* Fixing issue with generating expressions strings.
A space should not be added before the first item.