build: use NuGet Gettext.Tools for msgfmt on WIN32

Use the nuget_install() function introduced in 3b05adf (build: add
nuget_install() in cmake/NuGet.cmake, 2022-02-10) to download the
Gettext.Tools package for the msgfmt utility on Windows if it's not
available.

Signed-off-by: Rafael Kitover <rkitover@gmail.com>

contrib/buildsystems/CMakeLists.txt

@@ -221,18 +221,22 @@ if(WIN32 AND NOT MSVC)#not required for visual studio builds
 	endif()
 endif()
 
-if(NO_GETTEXT)
-	message(STATUS "msgfmt not used under NO_GETTEXT")
-else()
+
+find_program(MSGFMT_EXE msgfmt)
+
+if(NOT MSGFMT_EXE)
+	if(WIN32)
+		include(NuGet)
+		nuget_install(Gettext.Tools)
+	endif()
+
+	unset(MSGFMT_EXE)
+	unset(MSGFMT_EXE CACHE)
+
 	find_program(MSGFMT_EXE msgfmt)
+
 	if(NOT MSGFMT_EXE)
-		if(USE_VCPKG)
-			set(MSGFMT_EXE ${CMAKE_SOURCE_DIR}/compat/vcbuild/vcpkg/downloads/tools/msys2/msys64/usr/bin/msgfmt.exe)
-		endif()
-		if(NOT EXISTS ${MSGFMT_EXE})
-			message(WARNING "Text Translations won't be built")
-			unset(MSGFMT_EXE)
-		endif()
+		message(WARNING "msgfmt not available and/or could not be installed, text translations won't be built.")
 	endif()
 endif()