Improve OpenModelica support of ThermoSysPro

Since ThermoSysPro has been developed mainly with Dymola, ensure that the library is fully supported by OpenModelica (compliancy with official Modelica spec, graphical annotations, ...).

Useful material and hints can be found here:

https://trac.openmodelica.org/OpenModelica/wiki/WritingCompliantLibraries

https://openmodelica.org/doc/OpenModelicaUsersGuide/latest/porting.html