build(vite): replace webpack with Vite, add Typescript (#1594)

BREAKING: mixins are no longer exported from the index (and will likely be converted to hooks)

tsconfig.vite-config.json

@@ -0,0 +1,8 @@
+{
+  "extends": "@vue/tsconfig/tsconfig.node.json",
+  "include": ["vite.config.*"],
+  "compilerOptions": {
+    "composite": true,
+    "types": ["node", "vitest"]
+  }
+}