Re-writing ImTui (ImGui curses backend)

[katemonster33]

Summary

Infrastructure "refactored ImTuis drawing code to fix a black screen issue, and to improve performance"

Purpose of change

Fixes: #73031
Fixes: #73392

Describe the solution

ImTui was using a single ncurses window to draw all its data. this window encompasses the whole screen, which meant that no matter what, when that window was refreshed the first time, the screen would be blacked out.

The new and improved ImTui uses several windows based on the windows ImGui is attempting to draw. This means that ImTui can't overwrite cells on the terminal outside of where a window is meant to be drawn.

Describe alternatives you've considered

Testing

load the game, verify you are not greeted with a black screen.

also verify that any spaces where an ImTui window was drawn are overwritten, as expected, when it is closed. this part got rolled into #73426

Additional context

During my testing I was working a lot with WSL, and found this weird case where, if you build CDDA from a fresh copy with no localization, every time you start the game you get the same black screen bug and you have to press a key to show the language selection. I couldn't reproduce it in Linux so I wrote it off as unrelated.-

[katemonster33]

i devised a way i can optimize this so I don't need the TWindow struct and all the calculations needed to get the window bounds. I am going to mark as draft so I can try to implement it