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/common/dynamic_library/dynamic_library.cpp

@@ -38,7 +38,7 @@ bool DynamicLibrary::Load(std::string_view filename) {
     if (!handle) {
         DWORD error_message_id = GetLastError();
         LPSTR message_buffer = nullptr;
-        size_t size =
+        std::size_t size =
             FormatMessageA(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
                                FORMAT_MESSAGE_IGNORE_INSERTS,
                            nullptr, error_message_id, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),