AK: Explicitly instantiate String::to_uint<unsigned long{, long}>()

Instead of just to_uint<u64>().

AK/String.cpp

@@ -179,7 +179,8 @@ Optional<T> String::to_uint(TrimWhitespace trim_whitespace) const
 template Optional<u8> String::to_uint(TrimWhitespace) const;
 template Optional<u16> String::to_uint(TrimWhitespace) const;
 template Optional<u32> String::to_uint(TrimWhitespace) const;
-template Optional<u64> String::to_uint(TrimWhitespace) const;
+template Optional<unsigned long> String::to_uint(TrimWhitespace) const;
+template Optional<unsigned long long> String::to_uint(TrimWhitespace) const;
 
 bool String::starts_with(StringView str, CaseSensitivity case_sensitivity) const
 {