Rename and fix if/conditional in ExpressionBuilder 

This is a minor change that renames and fixes a previously badly named and _broken_ feature of ```ExpressionBuilder```. Closes #4470.
These statements are always preceded by a quote character on the same line, which shouldn't be the case in C++ unless you are doing something like:
```cpp
std::string s("string"); if(s == "string")...
```
But, I would hope that are code review would catch this rather than the pre_test.