Merge #5491

5491: Move twping to tools directory r=heinrich5991 a=def-

<!-- What is the motivation for the changes of this pull request -->

## Checklist

- [ ] Tested the change ingame
- [ ] Provided screenshots if it is a visual change
- [ ] Tested in combination with possibly related configuration options
- [ ] Written a unit test if it works standalone, system.c especially
- [ ] Considered possible null pointers and out of bounds array indexing
- [ ] Changed no physics that affect existing maps
- [ ] Tested the change with [ASan+UBSan or valgrind's memcheck](https://github.com/ddnet/ddnet/#using-addresssanitizer--undefinedbehavioursanitizer-or-valgrinds-memcheck) (optional)


Co-authored-by: Dennis Felsing <dennis@felsin9.de>

CMakeLists.txt

@@ -2401,14 +2401,6 @@ endif()
 ########################################################################
 
 if(TOOLS)
-  set_src(TWPING_SRC GLOB src/twping twping.cpp)
-  set(TARGET_TWPING twping)
-  add_executable(${TARGET_TWPING} EXCLUDE_FROM_ALL ${TWPING_SRC} $<TARGET_OBJECTS:engine-shared> ${DEPS})
-  target_link_libraries(${TARGET_TWPING} ${LIBS})
-
-  list(APPEND TARGETS_OWN ${TARGET_TWPING})
-  list(APPEND TARGETS_LINK ${TARGET_TWPING})
-
   set(TARGETS_TOOLS)
   set_src(TOOLS_SRC GLOB src/tools
     config_common.h
@@ -2426,6 +2418,7 @@ if(TOOLS)
     map_resave.cpp
     packetgen.cpp
     stun.cpp
+    twping.cpp
     unicode_confusables.cpp
     uuid.cpp
   )