* feat: add privilege give/rescind hooks
action:privileges.categories.give/rescind
action:privileges.global.give/rescind
breaking change, privileges.categories.give/rescind and privileges.global.give/rescind use full privilege name for groups ie `groups:find` instead of `find`
* fix: tests, privileges renamed
new method emptydb
use emptydb instead of flushdb, flushdb removes indices for mongo which
breaks search tests
initialize meta.config properly in tests
enable nodebb-plugin-dbsearch for tests