Automate setting up toolkit builds in a webview environment for testing

[hawkticehurst]

Feature/component description

Create a Node script that automates the steps required to copy a new toolkit build into a webview extension environment so that it can be manually/visually tested.

Use case

Currently, the process of testing toolkit builds inside a webview takes around 11 manual steps and is a process ripe for being improved with some automation so the barrier to testing new builds is reduced.