Add support for Hindi, Bengali, Tamil etc languages

Add a dropdown inside the popup such that the user can select which language words are to be applied on the given pages.

For the time being, let's just stick to the words given inside the dictionary for english to kannada.

Note: Language support for each specific language needs to be a separate PR, so please do not combine them.

Start by locating the popup entry point and the English-to-Kannada dictionary used on pages. Confirm how the popup applies words, then add a language selector limited to the existing dictionary; done means the selected language controls which words are applied, without combining other language support in this change.

Written by the indexing model from the issue text.