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/string_literal.h

@@ -9,7 +9,7 @@
 
 namespace Common {
 
-template <size_t N>
+template <std::size_t N>
 struct StringLiteral {
     constexpr StringLiteral(const char (&str)[N]) {
         std::copy_n(str, N, value);