Wagtail-cjkcms

Added
- Support for breadcrumbs per-page visibility
- breadcrumb_title page property for all CMS pages, choosing new "breadcrumb_label" field or page title if new field empty
- Added new templatetag with tests: first_not_empty which returns first not empty argument from the list, e.g. {% first_not_empty var1 var2 var3 %}

Fixed
- Update malformed robots.txt file

Fixed
- Fixed responsiveness of the 404 template

Added
- HighlightBlock, allows an element to stand out with the ability to change the colour of the background, border, text from the basic bootstrap colour palette also allows an icon to be added

Added
- API endpoint to allow remote monitoring of software component versions. Disabled by default. See /docs/api/version_monitor.md for details

Changed
- MDBootstrap kit updated to 7.3.0
- Restored availability of MDBootstrap CDN ich choice of Bootstrap themes
- Updated dropdown init code in base_link_block to work with MDBootstrap 7.3.0+
Fixed
- Dark theme was incorrectly forced when MDB was in use; now respects the choice in backend->settings->layout