We assume that `char` is `signed` in various places in the code. In particular, the `Str.StrToInts` test will fail when `char` is not `signed` and names containing special characters will be displayed incorrectly on servers.
Therefore, the compiler flag `-fsigned-char` is set unconditionally instead of only for ARM and ARM64, as we expect `char` to be `signed` on all architectures.
A static assertion is added to ensure at compile time that `char` is `signed` independently from the flag added in `CMakeLists.txt`.
This is necessary at least for ARM, ARM64, PPC, PPC64, and PPC64LE. According to some sources, `char` may also be `unsigned` by default when compiling for Android, although this could not be confirmed with the current Android NDK using Clang.
For the PowerPC architectures, Compiler Explorer can be used to confirm that `char` is not `signed` by default by checking whether the static assertion compiles (see https://godbolt.org/z/9rn5Mrf59) and that the assembly is different with the `-fsigned-char` flag (see https://godbolt.org/z/138zTj3Wa).
Closes#8386.
Fix button logic being stuck when holding mouse button on UI elements with button logic in the menus/editor, switching between menus and editor with Ctrl+Shift+E, then using a UI element with button logic in the editor/menus and switching back.
Fix value selector text mode of color picker popups being deactivated when switching between menus and editor while the color picker popup is open in both.
Only update progress spinners once per frame in `CUi::Update` to ensure consistent rotation speed. Progress spinners in menus and editor now rotate independently.
In general, all `static` non-`const` variables in `CUi` are replaced with member variables, as the `static` variables are shared between the two `CUi` instances of the menus and the editor, causing the above issues.
The percentage of received console commands was not being shown with the progress spinner because the variable `ProgressProps` was not passed to the `RenderProgressSpinner` function.
