Rework Game UI

[SimplyLiz]

Remove the ui buttons at the bottom of the game and replace it by a new UI. There are several ideas on the discord server, but be creative :)

We need to show following:

• [ ] Building Menu in categories and subcategories, like we have now. (Terrain Edit, Roads, Zones, Water, Power, Emergency, Parks, Debug)
• [ ] Money count
• [ ] Population count
• [ ] RCI demand Indicators
• [ ] Settings button
• [ ] GameSpeed buttons (#843)

[lizzyd710]

Is this task for the imgui replacement, or just a different design? (Or both?)

[dalerank]

I want to move UI parts to imgui, I will do it with small parts, like commit for pause menu, another for settings

[lizzyd710]

With the UI overhaul to DearImGui, do you want me to still keep working on implementing Yusuf's mockup? (Albeit with the new framework)

[lainq]

What do you think about adding tooltips in the UI. The images are barely visible

[lizzyd710]

What do you think about adding tooltips in the UI. The images are barely visible

I think that would be very helpful--but when the UI was completely overhauled to that framework, I am no longer familiar with how the UI works and would have to look into it or hope someone knows how to do it. But that is a very good idea!