amadeus: Add missing compressor effect from REV11 (#4010)

* amadeus: Add missing compressor effect from REV11

This was in my reversing notes but seems I completely forgot to
implement it

Also took the opportunity to simplify the Limiter effect a bit.

* Remove some outdated comment

* Address gdkchan's comments

Ryujinx.Audio/Renderer/Server/Effect/CompressorEffect.cs

@@ -0,0 +1,67 @@
+using Ryujinx.Audio.Renderer.Common;
+using Ryujinx.Audio.Renderer.Dsp.State;
+using Ryujinx.Audio.Renderer.Parameter.Effect;
+using Ryujinx.Audio.Renderer.Parameter;
+using Ryujinx.Audio.Renderer.Server.MemoryPool;
+using System;
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+
+namespace Ryujinx.Audio.Renderer.Server.Effect
+{
+    /// <summary>
+    /// Server state for a compressor effect.
+    /// </summary>
+    public class CompressorEffect : BaseEffect
+    {
+        /// <summary>
+        /// The compressor parameter.
+        /// </summary>
+        public CompressorParameter Parameter;
+
+        /// <summary>
+        /// The compressor state.
+        /// </summary>
+        public Memory<CompressorState> State { get; }
+
+        /// <summary>
+        /// Create a new <see cref="CompressorEffect"/>.
+        /// </summary>
+        public CompressorEffect()
+        {
+            State = new CompressorState[1];
+        }
+
+        public override EffectType TargetEffectType => EffectType.Compressor;
+
+        public override ulong GetWorkBuffer(int index)
+        {
+            return GetSingleBuffer();
+        }
+
+        public override void Update(out BehaviourParameter.ErrorInfo updateErrorInfo, ref EffectInParameterVersion1 parameter, PoolMapper mapper)
+        {
+            // Nintendo doesn't do anything here but we still require updateErrorInfo to be initialised.
+            updateErrorInfo = new BehaviourParameter.ErrorInfo();
+        }
+
+        public override void Update(out BehaviourParameter.ErrorInfo updateErrorInfo, ref EffectInParameterVersion2 parameter, PoolMapper mapper)
+        {
+            Debug.Assert(IsTypeValid(ref parameter));
+
+            UpdateParameterBase(ref parameter);
+
+            Parameter = MemoryMarshal.Cast<byte, CompressorParameter>(parameter.SpecificData)[0];
+            IsEnabled = parameter.IsEnabled;
+
+            updateErrorInfo = new BehaviourParameter.ErrorInfo();
+        }
+
+        public override void UpdateForCommandGeneration()
+        {
+            UpdateUsageStateForCommandGeneration();
+
+            Parameter.Status = UsageState.Enabled;
+        }
+    }
+}