Consolidate third-party plugins into Assets/Plugins

Move and consolidate many third-party plugin files and metadata from various locations (notably Assets/Third Parties/Plugins 1 and scattered Opsive/Photon folders) into a unified Assets/Plugins directory. Includes DOTween, PrimeTween, Native/BackroomsNoise, Sirenix/Odin Inspector, and Opsive UltimateCharacterController/shared libs, plus updates to several .meta files and removal of obsolete installer/legacy files. This standardizes plugin layout and cleans up duplicate/obsolete assets.

Assets/Third Parties/Opsive/Shared/Editor/Utility/Opsive.Shared.Editor.Utility.dll.meta

@@ -0,0 +1,33 @@
+fileFormatVersion: 2
+guid: a631ef662744ace4ea3db11f84b017a9
+PluginImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  iconMap: {}
+  executionOrder: {}
+  defineConstraints: []
+  isPreloaded: 0
+  isOverridable: 0
+  isExplicitlyReferenced: 0
+  validateReferences: 1
+  platformData:
+  - first:
+      Any: 
+    second:
+      enabled: 0
+      settings: {}
+  - first:
+      Editor: Editor
+    second:
+      enabled: 1
+      settings:
+        DefaultValueInitialized: true
+  - first:
+      Windows Store Apps: WindowsStoreApps
+    second:
+      enabled: 0
+      settings:
+        CPU: AnyCPU
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: