Flarum beta 16 compatibility

Adds compatibility for Flarum beta 16

Export, Import, Coverage and more

• Added Yaml export feature
• Added Yaml import feature
• Added coverage report
• Added frontend filter
• Added more options to missing translations filter
• Added mass delete actions
• Improved extension filter to also list unrecognized namespaces

Update sponsored by Glowing Blue

Beta 13 backport

• Backport fix for #22 for beta 13

0.5.0

Bundled output for commit a1a8d6844b9cb7beda88b9271538ae135b174ea8 [s…