Custom utilities are replaced by libraries

[MikkCZ]

There are two lists with interesting libraries, that might be applicable to replace some custom code in Pontono Add-on

• https://github.com/fregante/webext-fun
• https://github.com/fregante/Awesome-WebExtensions
• https://www.npmjs.com/package/@temple-wallet/jest-webextension-mock?activeTab=readme

If they do what I implemented in this extension, let's use them instead to reduce the ammount of custom code that needs to be maintained here. If not, consider creating PRs to those libraries to extend them with the functionality needed, and/or move the code and publish it as standalone packages instead, with the hope that one day someone can adopt it as well.