Merge branch 'plugin-377' into 'master'

Add a plugin for XEP-0377: spam reporting

See merge request poezio/slixmpp!53
2 jobs for master in 1 minute and 56 seconds (queued for 2 seconds)
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Status Job ID Name Coverage
  Test
passed #28806
docker
test

00:01:36

 
  Trigger
passed #28807
docker
trigger_poezio

00:00:20