[cmake] Add SPINE_SET_COMPILER_FLAGS (#2698)

* Add SPINE_SET_COMPILER_FLAGS

* remove newline

flags.cmake

@@ -1,4 +1,9 @@
 option(SPINE_SANITIZE "Build with sanitization" OFF)
+option(SPINE_SET_COMPILER_FLAGS "Set compiler flags" ON)
+
+if (NOT SPINE_SET_COMPILER_FLAGS)
+    return();
+endif()
 
 if(MSVC)
     message("MSCV detected")
@@ -11,4 +16,4 @@ else()
         set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -fsanitize=address -fsanitize=undefined")
         set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -fsanitize=address -fsanitize=undefined")
     endif()
-endif()
+endif()