misc: fix issues pointed out by msvc (#7316)

* do not move constant variables

* applet_manager: avoid possible use after move

* use constant references where pointed out by msvc

* extra_hid: initialize response

* ValidateSaveState: passing slot separately is not necessary

* common: mark HashCombine as nodiscard

* cityhash: remove use of using namespace std

* Prefix all size_t with std::

done automatically by executing regex replace `([^:0-9a-zA-Z_])size_t([^0-9a-zA-Z_])` -> `$1std::size_t$2`
based on 7d8f115

* shared_memory.cpp: fix log error format

* fix compiling with pch off

src/core/hle/service/apt/applet_manager.cpp

@@ -713,6 +713,7 @@ Result AppletManager::SendDspSleep(AppletId from_applet_id,
             .signal = SignalType::DspSleep,
             .object = std::move(object),
         });
+        return ResultSuccess;
     }
 
     auto sys_lib_slot = GetAppletSlotFromPos(AppletPos::SysLibrary);
@@ -728,6 +729,7 @@ Result AppletManager::SendDspSleep(AppletId from_applet_id,
             .signal = SignalType::DspSleep,
             .object = std::move(object),
         });
+        return ResultSuccess;
     }
 
     return ResultSuccess;