SCons: Add two new COMSTR environment variables

[Repiteo]

This PR aims to make the output logs of a non-verbose build more uniform by adding two new environment variables: RCCOMSTR and GENCOMSTR. RCCOMSTR is an existing keyword for SCons, used for compiling .rc files into .res/.o, so adding it eliminates the last remaining verbose output (on Windows anyway). GENCOMSTR is a bit more involved, as it effectively replaces the methods.Run "short_message" argument. However, because it's now formatted to automatically reference the generated file, the original messages are no longer needed

[YuriSizov]

Can you give some examples of the effect of these changes?

[Repiteo]

Sure!

RCCOMSTR

Before:

rc /DTOOLS_ENABLED /DDEBUG_ENABLED /DDEV_ENABLED /DNO_EDITOR_SPLASH /DWINDOWS_ENABLED /DWASAPI_ENABLED /DWINMIDI_ENABLED /DTYPED_METHOD_BIND /DWIN32 /DWINVER=0x0601 /D_WIN32_WINNT=0x0601 /DNOMINMAX /D_WIN64 /DVULKAN_ENABLED /DGLES3_ENABLED /D_HAS_EXCEPTIONS=0 /DMINIZIP_ENABLED /DBROTLI_ENABLED /DCLIPPER2_ENABLED /DZSTD_STATIC_LINKING_ONLY /DUSE_VOLK /DVK_USE_PLATFORM_WIN32_KHR /DGLAD_ENABLED /DEGL_ENABLED /Ithirdparty\freetype\include /Ithirdparty\libpng /Ithirdparty\glad /Ithirdparty\volk /Ithirdparty\vulkan /Ithirdparty\vulkan\include /Ithirdparty\zstd /Ithirdparty\zlib /Ithirdparty\clipper2\include /Ithirdparty\brotli\include /Ithirdparty\angle\include /Iplatform\windows /I. /nologo /foplatform\windows\godot_res_wrap.windows.editor.dev.x86_64.obj platform\windows\godot_res_wrap.rc

After:

Creating Compiled Resource platform\windows\godot_res_wrap.windows.editor.dev.x86_64.obj ...

GENCOMSTR

Before:

Building RD_GLSL header: "servers\rendering\renderer_rd\shaders\blit.glsl.gen.h"
Building GLES3 GLSL header: "drivers\gles3\shaders\copy.glsl.gen.h"
Building application icon.
Building splash screen header.
Generating enabled modules header.

After:

Generating servers\rendering\renderer_rd\shaders\blit.glsl.gen.h ...
Generating drivers\gles3\shaders\copy.glsl.gen.h ...
Generating main\app_icon.gen.h ...
Generating main\splash.gen.h ...
Generating modules\modules_enabled.gen.h ...

[Calinou]

Tested locally (with progress=no and rebased on top of master dad6c77), it works as expected on Windows 11 23H2 + Visual Studio 2022.

It also works when applied at the same time as #87154.

[akien-mga]

Thanks!