Drop content_sao.{cpp,h}

Move LuaEntitySAO to a new dedicated file
Drop TestSAO (useless object)
Drop the old static startup initialized SAO factory, which was pretty useless.
This factory was using a std::map for 2 elements, now just use a simple condition owned by ServerEnvironment, which will be lightweight, that will also drop a one time useful test on each LuaEntitySAO creation. This should reduce server load on massive SAO creation

src/server/CMakeLists.txt

@@ -1,5 +1,6 @@
 set(server_SRCS
 	${CMAKE_CURRENT_SOURCE_DIR}/activeobjectmgr.cpp
+	${CMAKE_CURRENT_SOURCE_DIR}/luaentity_sao.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/mods.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/player_sao.cpp
 	${CMAKE_CURRENT_SOURCE_DIR}/serveractiveobject.cpp