UICommon: Make use of fmt where applicable

Continues the migration to using fmt.

Notably, this allows safely converting a map within USBUtils over to
containing string view instances, rather than std::string instances, as
fmt safely handles the formatting of string views.

Source/Core/UICommon/Disassembler.h

@@ -5,6 +5,7 @@
 #pragma once
 
 #include <memory>
+#include <string>
 #include "Common/CommonTypes.h"
 
 class HostDisassembler