Store persistent metadata for a data item

[simonrjones]

Purpose is to cache metadata about page URLs on the frontend, in order to enable other functionality such as:

• Return how to get data for current page (useful for pages with any URL)
• Return frontend URL for an item in the CMS (e.g. WordPress)
• Initial API skeleton, which we can then add functionality to clear cache for a page, link to view page in CMS, preview page in CMS
• Generate breadcrumb for current page
• Generate Google Sitemap
• Generate RSS feeds (need to use GUID which does not change for RSS feeds)

Work

• Iterate through all routes (list pages & single pages), build page URLs
• Save metadata to local DB cache
  • URL
  • Page title
  • Data source (wordpress, rest)
  • Data source ID (e.g. CMS ID)
  • Cache keys used to generate page (so we can clear cache)
• Build PHP API to query DB cache
• Build REST API to query DB cache (api/v1/site/*)
• Add auth layer (auth tokens) to access data
• CLI command to build site cache

Look at storing this in SQLite.