Common: Validate the number of {} fields in format strings

Unfortunately, {fmt} allows passing too many arguments to a format call
without raising any runtime or compile-time error [1].

As this is a common source of bugs since we started migrating to {fmt},
this commit adds some custom logic to validate the number of
replacement fields in format strings in addition to {fmt}'s own checks.

[1] https://github.com/fmtlib/fmt/issues/492

Source/Core/Common/CMakeLists.txt

@@ -53,6 +53,7 @@ add_library(common
   Flag.h
   FloatUtils.cpp
   FloatUtils.h
+  FormatUtil.h
   FPURoundMode.h
   GekkoDisassembler.cpp
   GekkoDisassembler.h