Initial gem dependencies (#4229)

These are immediate dependencies, and include many circular dependencies, largely amongst the Atom gems, as indicated by cmake

Signed-off-by: AMZN-alexpete <26804013+AMZN-alexpete@users.noreply.github.com>

Gems/ScriptCanvasTesting/gem.json

@@ -5,9 +5,20 @@
     "origin": "Open 3D Engine - o3de.org",
     "type": "Tool",
     "summary": "The Script Canvas Testing Gem provides a framework for testing for and with Script Canvas.",
-    "canonical_tags": ["Gem"],
-    "user_tags": ["Scripting", "Debug", "Framework"],
+    "canonical_tags": [
+        "Gem"
+    ],
+    "user_tags": [
+        "Scripting",
+        "Debug",
+        "Framework"
+    ],
     "icon_path": "preview.png",
     "requirements": "",
-    "documentation_url": "https://o3de.org/docs/user-guide/gems/reference/script/script-canvas-testing/"
+    "documentation_url": "https://o3de.org/docs/user-guide/gems/reference/script/script-canvas-testing/",
+    "dependencies": [
+        "ScriptCanvas",
+        "GraphCanvas",
+        "ScriptEvents"
+    ]
 }