Organelle upgrades can be refunded in multicellular editor for infinite MP with multiple cell type edits

[hhyyrylainen]

Steps:

• Get to multicellular editor
• Modify a cell type and place a slime jet and modify it into a mucocyst
• Hit "next" and then start modifying the cell type again
• Modify the mucocyst back into a slime jet
• This incorrect refunds 20 MP

The steps can then be repeated infinitely by going back to edit the cell type, adding a cytoplasm and modifying the slime jet twice to go back to mucocyst for free and then refund the upgrade again for 20 MP. Repeat these steps to get over 100 MP:

I think this is a new bug but seems pretty closely related to:

• Undoing organelle upgrades in later editor cycle should not refund the full amount #4095
• Multicellular edits of multiple cells can still result in MP being incorrectly refunded #5010
• Modifying chemoreceptor in multicellular doesn't stick (gets reverted) #3816