Better check for valid items in the queue

[ubereffect]

Not an issue with this mod, but you can queue multiple copies of unique wonders, districts, and unrepeatable projects in the same city. This bug happens in vanilla (without mods). Another mod that changes the production panel fixed this bug, I figure CQUI could do so as well.

[ubereffect]

Issue still present with latest version of CQUI posted on GitHub yesterday. I also managed to queue multiple copies of buildings, within districts.

[Azurency]

I had a chat with the developers about this subject 🙈, it's a choice they made because predicting valid moves with the queue is a big problem. They decided to do the least amount of processing and let the current queue item check itself with the rules, otherwise the late game would take a long time to process.

That being said it's still fell stupid to me to be able to queue 5 monuments for exemple, so maybe there'll be a "fix" in the future.