test: add token snapshot tests (#8050)

**Related Issue:** n/a

## Summary

Adds a debugger script for calcite-design-tokens in VSCode (launch.json)
Adds snapshot tests to enforce token output

Author: alisonailea

.vscode/launch.json

@@ -66,6 +66,17 @@
       "skipFiles": ["<node_internals>/**"],
       "internalConsoleOptions": "neverOpen",
       "console": "integratedTerminal"
+    },
+    {
+      "type": "node",
+      "request": "launch",
+      "name": "Debug Tokens --spec {currentFile}",
+      "cwd": "${workspaceFolder}/packages/calcite-design-tokens",
+      "sourceMaps": true,
+      "runtimeArgs": ["--inspect-brk", "${workspaceRoot}/node_modules/jest/bin/jest.js", "--runInBand", "${file}"],
+      "skipFiles": ["<node_internals>/**"],
+      "internalConsoleOptions": "neverOpen",
+      "console": "integratedTerminal"
     }
   ]
 }