port InvokeAI API client to Unity, use it in ImageGenerationBox

Packages/manifest.json

@@ -13,6 +13,7 @@
     "com.unity.ide.vscode": "1.2.5",
     "com.unity.inputsystem": "1.5.0",
     "com.unity.memoryprofiler": "1.0.0",
+    "com.unity.nuget.newtonsoft-json": "3.2.2",
     "com.unity.postprocessing": "3.2.2",
     "com.unity.probuilder": "5.0.6",
     "com.unity.progrids": "3.0.3-preview.6",

Packages/packages-lock.json

@@ -152,6 +152,13 @@
       },
       "url": "https://packages.unity.com"
     },
+    "com.unity.nuget.newtonsoft-json": {
+      "version": "3.2.2",
+      "depth": 0,
+      "source": "registry",
+      "dependencies": {},
+      "url": "https://packages.unity.com"
+    },
     "com.unity.postprocessing": {
       "version": "3.2.2",
       "depth": 0,