IPC refactor part 3+4: New server HIPC message processor (#4188)

* IPC refactor part 3 + 4: New server HIPC message processor with source generator based serialization

* Make types match on calls to AlignUp/AlignDown

* Formatting

* Address some PR feedback

* Move BitfieldExtensions to Ryujinx.Common.Utilities and consolidate implementations

* Rename Reader/Writer to SpanReader/SpanWriter and move to Ryujinx.Common.Memory

* Implement EventType

* Address more PR feedback

* Log request processing errors since they are not normal

* Rename waitable to multiwait and add missing lock

* PR feedback

* Ac_K PR feedback

Ryujinx.Common/Memory/SpanReader.cs

@@ -0,0 +1,51 @@
+using System;
+using System.Runtime.CompilerServices;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.Common.Memory
+{
+    public ref struct SpanReader
+    {
+        private ReadOnlySpan<byte> _input;
+
+        public int Length => _input.Length;
+
+        public SpanReader(ReadOnlySpan<byte> input)
+        {
+            _input = input;
+        }
+
+        public T Read<T>() where T : unmanaged
+        {
+            T value = MemoryMarshal.Cast<byte, T>(_input)[0];
+
+            _input = _input.Slice(Unsafe.SizeOf<T>());
+
+            return value;
+        }
+
+        public ReadOnlySpan<byte> GetSpan(int size)
+        {
+            ReadOnlySpan<byte> data = _input.Slice(0, size);
+
+            _input = _input.Slice(size);
+
+            return data;
+        }
+
+        public T ReadAt<T>(int offset) where T : unmanaged
+        {
+            return MemoryMarshal.Cast<byte, T>(_input.Slice(offset))[0];
+        }
+
+        public ReadOnlySpan<byte> GetSpanAt(int offset, int size)
+        {
+            return _input.Slice(offset, size);
+        }
+
+        public void Skip(int size)
+        {
+            _input = _input.Slice(size);
+        }
+    }
+}