refactor(sonar): more small fixes

- std::format instead of iostream manipulators in to_string/to_hex_str (cpp:S6495);
  output verified identical, negative hex values keep the unsigned form
- remove an empty compound statement (cpp:S108)
- drop an always-false unsigned < 0 branch (cpp:S1768)
- explicit lambda capture (cpp:S3608)
- std::make_unique (cpp:S5950)

vehicle/Train.cpp

@@ -10033,8 +10033,6 @@ void TTrain::update_sounds(double const Deltatime)
 #ifdef _WIN32
 			Console::BitsClear(1 << 14); // ustawienie bitu 16 na PoKeys
 #endif
-		}
-
 		}
 
 		if (dsbBuzzerShp && dsbBuzzerShp->is_playing())