`discourse-common` was created in the past to share logic between the
'wizard' app and the main 'discourse' app. Since then, the wizard has
been consolidated into the main app, so the separation of
`discourse-common` is no longer useful.
This commit moves `discourse-common/(lib|utils)/*` into
`discourse/lib/*`, adds shims for the imports, and updates existing
uses in core.
At the moment, there is no way to create a group of related watched words together. If a user needed a set of words to be created together, they'll have to create them individually one at a time.
This change attempts to allow related watched words to be created as a group. The idea here is to have a list of words be tied together via a common `WatchedWordGroup` record. Given a list of words, a `WatchedWordGroup` record is created and assigned to each `WatchedWord` record. The existing WatchedWord creation behaviour remains largely unchanged.
Co-authored-by: Selase Krakani <skrakani@gmail.com>
Co-authored-by: Martin Brennan <martin@discourse.org>
