feat: add string utility tests and vitest browser configuration

src/utils/stringUtils.test.ts

@@ -0,0 +1,8 @@
+import { expect, describe, it } from 'vitest'
+import { round } from './stringUtils'
+
+describe('round', () => {
+  it('should be able to handle undefined input', () => {
+    expect(round(undefined)).toBe("");
+  });
+})