Add drupalSettings.xbData.v0 reference to starterComponentTemplate.ts

📌 Populate data to drupalSettings to enable Dynamic Code Components Active is in!

We will expose simple functions for code component authors to retrieve data from drupalSettings.xbData, so they don't need to deal with the Drupalism that is window.drupalSettings. Our initial discussion concluded that for title and breadcrumb, we'll most likely have a getPageData() function, and getSiteData() for base URL and branding. The issue(s) to make these happen are yet to be created. Nevertheless, good call to have some explanation added in the starter component template. Which is getting really long, so we'll want to link to online docs, but that's another issue that we'll need to create and work on. 🙂