feat: add RegisterResult component, ESLint config, and vue.config.js for project setup

- Created a new RegisterResult.vue component for displaying registration success.
- Added ESLint configuration for unit tests in the tests directory.
- Implemented vue.config.js for webpack configuration, including theme color support and proxy settings for development.

frontend_vue/.prettierrc

@@ -0,0 +1,6 @@
+{
+  "printWidth": 120,
+  "semi": false,
+  "singleQuote": true,
+  "prettier.spaceBeforeFunctionParen": true
+}