[Test] Standardise unit test infrastructure (#572)

* [Test] Revert custom name for test context

- Removes "lgTest", replaces with default "test"

* nit - Rename test extensions file

* Split test graphs out to separate file

test/assets/testGraphs.ts

@@ -0,0 +1,63 @@
+import type { ISerialisedGraph, SerialisableGraph } from "@/litegraph"
+
+export const oldSchemaGraph: ISerialisedGraph = {
+  version: 0.4,
+  config: {},
+  last_node_id: 0,
+  last_link_id: 0,
+  groups: [
+    {
+      id: 123,
+      bounding: [20, 20, 1, 3],
+      color: "#6029aa",
+      font_size: 14,
+      title: "A group to test with",
+    },
+  ],
+  nodes: [
+    {
+      id: 1,
+    },
+  ],
+  links: [],
+}
+
+export const minimalSerialisableGraph: SerialisableGraph = {
+  version: 1,
+  config: {},
+  state: {
+    lastNodeId: 0,
+    lastLinkId: 0,
+    lastGroupId: 0,
+    lastRerouteId: 0,
+  },
+  nodes: [],
+  links: [],
+  groups: [],
+}
+
+export const basicSerialisableGraph: SerialisableGraph = {
+  version: 1,
+  config: {},
+  state: {
+    lastNodeId: 0,
+    lastLinkId: 0,
+    lastGroupId: 0,
+    lastRerouteId: 0,
+  },
+  groups: [
+    {
+      id: 123,
+      bounding: [20, 20, 1, 3],
+      color: "#6029aa",
+      font_size: 14,
+      title: "A group to test with",
+    },
+  ],
+  nodes: [
+    {
+      id: 1,
+    },
+  ],
+  links: [],
+}