allow users to provide library version

[arun3688]

Purpose

This PR allows users to provide library Versions using the ModelicaSystem constructor

Example

>>> ModelicaSystem("TestVersion.mo", "Test", ["Modelica", "PowerSystems"]) # usage 1, as list of strings
>>> ModelicaSystem("TestVersion.mo", "Test", [("Modelica","3.2.3")]) # usage 2, as array of tuples 
>>> ModelicaSystem("TestVersion.mo", "Test", [("Modelica","3.2.3"), "PowerSystems"]) # usage 3, as Array of tuples and  String