Everywhere: Prefer using {:#x} over 0x{:x}

We have a dedicated format specifier which adds the "0x" prefix, so
let's use that instead of adding it manually.

Userland/Libraries/LibWasm/Parser/Parser.cpp

@@ -158,7 +158,7 @@ ParseResult<FunctionType> FunctionType::parse(InputStream& stream)
         return with_eof_check(stream, ParseError::ExpectedKindTag);
 
     if (tag != Constants::function_signature_tag) {
-        dbgln("Expected 0x60, but found 0x{:x}", tag);
+        dbgln("Expected 0x60, but found {:#x}", tag);
         return with_eof_check(stream, ParseError::InvalidTag);
     }