LibAudio+LibCore: Remove unnecessary IODeviceStreamReader.h

IODeviceStreamReader isn't pulling its weight.
It's essentially a subset of InputFileStream with only one user
(WavLoader).

This refactors WavLoader to use InputFileStream instead.

Userland/Libraries/LibCore/IODeviceStreamReader.h

@@ -1,41 +0,0 @@
-/*
- * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#pragma once
-
-#include <AK/StdLibExtras.h>
-#include <LibCore/IODevice.h>
-
-namespace Core {
-
-class IODeviceStreamReader {
-public:
-    IODeviceStreamReader(IODevice& device)
-        : m_device(device)
-    {
-    }
-
-    bool handle_read_failure()
-    {
-        return exchange(m_had_failure, false);
-    }
-
-    template<typename T>
-    IODeviceStreamReader& operator>>(T& value)
-    {
-        int nread = m_device.read((u8*)&value, sizeof(T));
-        VERIFY(nread == sizeof(T));
-        if (nread != sizeof(T))
-            m_had_failure = true;
-        return *this;
-    }
-
-private:
-    IODevice& m_device;
-    bool m_had_failure { false };
-};
-
-}