Merge branch 'remove-annotate-gem' into 'master'

Remove the annotate gem and delete old annotations

In 8278b763d96ef10c6494409b18b7eb541463af29 the default behaviour of annotation
has changes, which was causing a lot of noise in diffs. We decided in #17382
that it is better to get rid of the whole annotate gem, and instead let people
look at schema.rb for the columns in a table.

Fixes: #17382 

/cc @yorickpeterse 

See merge request !4099