[cmake] refactor configuration

* Split common stuff to reusable files
* Disable INTERPROCEDURAL_OPTIMIZATION for SDL2/3 resource targets

cmake/CheckAndSetFlag.cmake

@@ -0,0 +1,28 @@
+include(CheckCCompilerFlag)
+include(CheckCXXCompilerFlag)
+
+macro(CheckAndSetFlag FLAG)
+  if(FLAG)
+    get_property(languages GLOBAL PROPERTY ENABLED_LANGUAGES)
+
+    unset(C_FLAG)
+    unset(CXX_FLAG)
+    if("C" IN_LIST languages)
+      check_c_compiler_flag("${FLAG}" C_FLAG)
+      if(C_FLAG)
+        string(APPEND CMAKE_C_FLAGS " ${FLAG}")
+      endif()
+    endif()
+
+    if("CXX" IN_LIST languages)
+      check_cxx_compiler_flag("${FLAG}" CXX_FLAG)
+      if(CXX_FLAG)
+        string(APPEND CMAKE_CXX_FLAGS " ${FLAG}")
+      endif()
+    endif()
+
+    if(NOT C_FLAG AND NOT CXX_FLAG)
+      message(WARNING "compiler does not support ${FLAG}")
+    endif()
+  endif()
+endmacro()