Added tenant landing page configuration
Tenant landing pages

Added a dedicated endpoint for tenant landing pages at
/api/tenant/landing-page. An array of landing page blocks will be returned
Tenant landing pages follow-up

 * 12 blocks rather than 6
 * Configured 5 default blocks so the default landing page looks prettier
 * `/api/tenant/landingPage` rather than `/api/tenant/landing-page`
 * Alphabetised landing page block rest model
 * Added a test utility to clear a tenant’s landing page
Tenant landing pages

* Added a search block
* Cleaned up config section for landing page
* Resolving image/video URLs in hashed paths
Merge branch 'landing-pages' of https://github.com/simong/Hilary into landing-pages
Switched createBlock function to opts object