feat: button loading, disabled(WIP), refactor to useButtonClasses, Spinner and vitest

vitest.config.ts

@@ -0,0 +1,12 @@
+import { defineConfig } from 'vitest/config'
+import vue from '@vitejs/plugin-vue'
+
+export default defineConfig({
+    plugins: [
+        vue(),
+    ],
+    test: {
+        globals: true,
+        environment: 'jsdom',
+    },
+})