Replaced GoogleTest submodule with FetchContent statement in CMake

.gitmodules

@@ -1,3 +0,0 @@
-[submodule "googletest/googletest"]
-	path = googletest/googletest
-	url = git@github.com:google/googletest.git

googletest/CMakeLists.txt

@@ -1,17 +1,14 @@
 # Copyright (c) Microsoft Corporation.
 # Licensed under the MIT License.
-add_subdirectory(googletest)
+include(FetchContent)
 
-# Note: Must set the code generation flag to Multi-threaded Debug (/MTd) to compile with Google Test
-# Workaround referenced from https://gitlab.kitware.com/cmake/community/-/wikis/FAQ
-foreach(flag_var CMAKE_CXX_FLAGS CMAKE_CXX_FLAGS_DEBUG CMAKE_CXX_FLAGS_RELEASE CMAKE_CXX_FLAGS_MINSIZEREL CMAKE_CXX_FLAGS_RELWITHDEBINFO)
-    if(${flag_var} MATCHES "/MD")
-        string(REGEX REPLACE "/MD" "/MT" ${flag_var} "${${flag_var}}")
-    endif()
-    if(${flag_var} MATCHES "/MDd")
-        string(REGEX REPLACE "/MDd" "/MTd" ${flag_var} "${${flag_var}}")
-    endif()
-endforeach()
+set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
+FetchContent_Declare(
+    googletest
+    GIT_REPOSITORY https://github.com/google/googletest.git
+    GIT_TAG master # Live at head
+)
+FetchContent_MakeAvailable(googletest)
 
 project(DirectX-Headers-GoogleTest-Suite CXX)
 add_executable(Feature-Support-Test feature_support_test.cpp)

googletest/googletest

@@ -1 +0,0 @@
-Subproject commit 8d51ffdfab10b3fba636ae69bc03da4b54f8c235