Some curses UI fixes

[Qrox]

Summary

SUMMARY: Interface "Some curses UI fixes"

Purpose of change

1. Only show the warning about the lack of utf-8 encoding once
2. Use the whole terminal for encoding/teminal size warnings.
3. Avoid returning from input_manager::get_input_event when resizing the terminal to match the tiles behavior.
4. Avoid re-entry into game::init_ui when showing encoding/terminal size warnings by not calling input_manager::wait_for_any_key.

Describe the solution

1. Move the check into the first_init branch.
2. Print to catacurses::stdscr.
3. Add a loop that only exits when getch() returns a value other than KEY_RESIZE.
4. Move the warning code to ncurses_def.cpp and use getch instead.

Testing

Tested on MSYS2.

1. Resized the terminal and the encoding warning no longer showed.
2. Resized the terminal and the whole screen was used.
3. Interacted with an in-game console, resized when prompted to enter any key, and the resizing was correctly handled instead of being handled as a key press.
4. Started the game / resized the terminal and the encoding/terminal size warnings were correctly closed by a key press / resizing the window, respectively.

[lgtm-com]

This pull request introduces 2 alerts when merging e09782e into b793146 - view on LGTM.com

new alerts:

• 2 for Function declared in block