Singularity function refactor

[JesseBonanno]

• Update from Piecewise functions to Singularity function for all load types to help with calculation speed and clarity.
• Loading moved to seperate file to help seperate code and to help stop circular dependency.
• Loading classes updated to be actual classes that inherit from parents.
• Analysis significantly shorter and more clear and concise. Removed several minor functions that arent very useful.
• Reimplemented the way plotting and getting max/min values for a function works to also save on speed. Slight improvements to dash app.