fix: Resolved the .dll dependency conflict in Unity 2021.2

Replaced .dll files with the dependencies on org.nuget packages

Author: SolidAlloy

Editor/DLLs.meta

@@ -15,8 +15,8 @@
     "overrideReferences": true,
     "precompiledReferences": [
         "UnityEngineInternals.dll",
-        "TypeReference_System.Memory.dll",
-        "TypeReference_System.Runtime.CompilerServices.Unsafe.dll"
+        "System.Memory.dll",
+        "System.Runtime.CompilerServices.Unsafe.dll"
     ],
     "autoReferenced": true,
     "defineConstraints": [],

Editor/DLLs/TypeReference_System.Buffers.dll

@@ -5,7 +5,9 @@
   "description": "A plugin that allows selecting a type from a drop-down menu in the inspector.",
   "dependencies": {
     "com.solidalloy.util": "1.33.1",
-    "com.unity.settings-manager": "1.0.3"
+    "com.unity.settings-manager": "1.0.3",
+    "org.nuget.system.memory": "4.5.4",
+    "org.nuget.system.runtime.compilerservices.unsafe": "5.0.0"
   },
   "keywords": [
     "dropdown",