Simplify two pores model

[PavelBal]

• Remove molecules FcRn Kinetics... and replace by container criteria of the respective reactions. ➡️ Open-Systems-Pharmacology/PK-Sim#2804
• "Extend" of Initial conditions: by default, do not extend for FcRn-complexes (e.g. "Fluvoxamine-FcRn_Complex") (== use PK-Sim knowledge). This should be managed by a check box (e.g. "Do not create for FcRn blabla..")
• Do not extend "LigandEndo", "FcRn", and "LigandEndo_Complex"
• Reactions "FcRn binding Fluvoxamine in endosomal/plasma/etc space" should use sum formulas for total amounts of molecules. -> Create parameter "TotalM" in the reaction summing up all amounts of this molecule in "Endosome" (example) and "TotalMC" for the complex. ➡️ Open-Systems-Pharmacology/PK-Sim#1347