Fixing and cleaning up handling of operator argument sourrounding the use of scientific notations

Scientific notation like 10e2 were not accepted by our conversion functions and caused a wrong "missing argument option" when used with options.

• fixed use of conversion function
• changed option handling to work better with the new functions
• added templated string to T where T= artihmetic function
• removed old split_with_seperator_function
• added exists function for checking if a string represents a module
• added extra stop requirement for argument parsing
• fixed naked stof which caused ugly error messages