feat: a more intuitive way to configure and override

[haoqunjiang]

Backwards compatibility is retained in this PR so there's no breaking changes.

The new defineConfig needs to alter the configs passed in to the following layout:

// [FIRST-EXTENDED-CONFIG]
// ...
// [LAST-EXTENDED-CONFIG]
//
// [BASIC SETUP]
//   pluginVue.configs['flat/base'],
//   '@vue/typescript/setup'
//
// [ALL-OTHER-TYPE-AWARE-RULES-CONFIGURED-BY-USERS]
//
// [ERROR PREVENTION & PERFORMANCE OPTIMIZATION]
//   '@vue/typescript/skip-type-checking-for-js-files'
//   '@vue/typescript/skip-type-checking-for-vue-files-without-ts'
//
// [ONLY REQUIRED WHEN ONE-OR-MORE TYPE-AWARE RULES ARE TURNED-ON]
//   '@vue/typescript/default-project-service-for-ts-files'
//   '@vue/typescript/default-project-service-for-vue-files'
//   '@vue/typescript/type-aware-rules-in-conflit-with-vue'

TODOs:

• Haven't decided if defineConfigWithVueTs is a good enough name;
• If defineConfigWithVueTs is omitted, the current error message isn't clear.
• Shall we append base automatically if the user forgets to add any of vueTsConfigs in the config file?

[haoqunjiang]

The PR is almost finished, and it works great with the upcoming rewrite of @vue/eslint-config-standard-with-typescript.
But I'm going for a family trip tomorrow… So let's review it until after the New Year.
Happy Holidays to anyone who sees this post!