cmake: Group blake2 targets under same directory for IDEs

The blake2_static target has no specific FOLDER property set and thus
would appear ungrouped in Visual Studio's Solution Explorer.

With this change both the default blake2 target as well as
blake2_static appear in their own "blake2" subdirectory.

deps/blake2/CMakeLists.txt

@@ -17,4 +17,7 @@ if(OS_WINDOWS)
 
   target_include_directories(blake2_static PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/src")
   set_target_properties(blake2_static PROPERTIES MSVC_RUNTIME_LIBRARY "MultiThreaded$<$<CONFIG:Debug>:Debug>")
+
+  set_target_properties(blake2 PROPERTIES FOLDER deps/blake2)
+  set_target_properties(blake2_static PROPERTIES FOLDER deps/blake2)
 endif()