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/aarch64/cpu_detect.cpp

@@ -30,7 +30,7 @@ namespace Common {
 #ifdef __APPLE__
 static std::string GetCPUString() {
     char buf[128];
-    size_t buf_len = sizeof(buf);
+    std::size_t buf_len = sizeof(buf);
     if (sysctlbyname("machdep.cpu.brand_string", &buf, &buf_len, NULL, 0) == -1) {
         return "Unknown";
     }