Single-object viewer POC (#14)

This commit implements a Sketchfab-style single-object viewer as a minimal
proof-of-concept.

### `@storyteller/studio-web`
This is a new package to house web components for interfacing with the
`@storyteller/studio` WASM library. It currently includes a single component,
`<sts-viewer />`, which is exported from `@storyteller/studio-web/viewer`.

### `react-frontend`
This is a new application intended as a proof-of-concept and testbed for React
interop with `@storyteller/studio-web`.

Web components are currently a little bit fiddly to use in a React application.
`react-frontend/src/app/studio-viewer.tsx` demonstrates how a React-idiomatic
component can be written as a thin wrapper around a web component, and
`react-frontend/src/app/app.tsx` demonstrates that wrapper component in use.

studio-web/project.json

@@ -0,0 +1,24 @@
+{
+  "name": "studio-web",
+  "$schema": "../node_modules/nx/schemas/project-schema.json",
+  "sourceRoot": "studio-web/src",
+  "projectType": "library",
+  "targets": {
+    "build": {
+      "executor": "@nx/vite:build",
+      "outputs": ["{options.outputPath}"],
+      "options": {
+        "outputPath": "dist/studio-web"
+      }
+    },
+    "test": {
+      "executor": "@nx/vite:test",
+      "outputs": ["{options.reportsDirectory}"],
+      "options": {
+        "passWithNoTests": true,
+        "reportsDirectory": "../coverage/studio-web"
+      }
+    }
+  },
+  "tags": []
+}