Migration to UI framework like React/Vue

This year for docFiller has been absolutely phenomenonal, from next to no use of UI to now, we at this moment use extensive UI in options and popup page for user preferences and analytics.

The common mode for UI was HTML, CSS and Vanilla JS(later typescript). But maintaining UI states using DOM is painful to manage and maintain.

So, we propose that we migrate to some framework like React, Vue etc(Open for discussion, but in Type safe variations). We have to ensure hot reloading works (in the way it is working now for Firefox and chromium).

Vitesse-webext does implement that but HMR doesnt work for Firefox for Manifest v3: https://github.com/antfu-collective/vitesse-webext! Rendering it unusable for us. We're looking for workaround in our codebase to make this happen.

This requires some changes in bundler, present under tools/ directory. Also, the change has to be incremental in nature rather than whole rewrite at once of our UI code.

Also, our code and utils will continue to exist in Typescript only!