Improve Building UI about unciv

[AutumnPizazz]

And we would add 3 properties for Buildings.json.

[kostia1st]

Maybe it's just simpler and more convenient to add a "Search" input box somewhere? Which would look for everything eventually, but we could start with just buildings for now

[AutumnPizazz]

No, no, no. The main reason I suggested this is that my mod may allow a city to have a large number of buildings, and players need to keep track of the number and types of buildings in each city, especially the capital, in real time (these buildings could be called global modifiers here). In the UI I envisioned, players can easily view each building instead of searching for a specific one.

[AutumnPizazz]

I need it, QAQ, help me plz. @SomeTroglodyte

[SomeTroglodyte]

I had a branch somewhere experimenting with that other issue's idea, the one with the nice mockup. Worked mostly... Not quite the same, but add some filtering, pretty similar. However, I'm currently not investing much energy here, psyche not really up to it. Patience.