This commit migrates all bookmarks to be polymorphic (using the
bookmarkable_id and bookmarkable_type) columns. It also deletes
all the old code guarded behind the use_polymorphic_bookmarks setting
and changes that setting to true for all sites and by default for
the sake of plugins.
No data is deleted in the migrations, the old post_id and for_topic
columns for bookmarks will be dropped later on.
A bit of a mixed bag, this addresses several edge areas of bookmarks and makes them compatible with polymorphic bookmarks (hidden behind the `use_polymorphic_bookmarks` site setting). The main ones are:
* ExportUserArchive compatibility
* SyncTopicUserBookmarked job compatibility
* Sending different notifications for the bookmark reminders based on the bookmarkable type
* Import scripts compatibility
* BookmarkReminderNotificationHandler compatibility
This PR also refactors the `register_bookmarkable` API so it accepts a class descended from a `BaseBookmarkable` class instead. This was done because we kept having to add more and more lambdas/properties inline and it was very messy, so a factory pattern is cleaner. The classes can be tested independently as well.
Some later PRs will address some other areas like the discourse narrative bot, advanced search, reports, and the .ics endpoint for bookmarks.
It's very easy to forget to add `require 'rails_helper'` at the top of every core/plugin spec file, and omissions can cause some very confusing/sporadic errors.
By setting this flag in `.rspec`, we can remove the need for `require 'rails_helper'` entirely.
When running an import script there are many site settings that are
changed but we reset them back to where they were originally before the
import. However, there are two settings that we don't roll back:
```
purge_unactivated_users_grace_period_days
purge_deleted_uploads_grace_period_days
```
which could have some unintended consequences.
My first question is do we *really* have to change these settings? I'm
not a huge fan of changing someones settings without them really knowing
they were changed.
If we really do have to change these settings here is my proposed PR
where we don't alter the `purge_unactivated_users_grace_period_days` if
it has been disabled.
As I'm writing this another change we could make is that we don't change
either of these site settings if we detect that they aren't set to the
default values.
The drive behind this PR is that there is a discourse instance which
relies on staged users as part of their workflow and this setting was
changed by accident via the import script causing users to be deleted
that shouldn't have been.
