The main thrust of this PR is to take all the conditional checks based on the `enable_bookmarks_with_reminders` away and only keep the code from the `true` path, making bookmarks with reminders the core bookmarks feature. There is also a migration to create `Bookmark` records out of `PostAction` bookmarks for a site.
### Summary
* Remove logic based on whether enable_bookmarks_with_reminders is true. This site setting is now obsolete, the old bookmark functionality is being removed. Retain the setting and set the value to `true` in a migration.
* Use the code from the rake task to create a database migration that creates bookmarks from post actions.
* Change the bookmark report to read from the new table.
* Get rid of old endpoints for bookmarks
* Link to the new bookmarks list from the user summary page
* Do not grant badges for posts with no user
* Ensure instructions are correct in Change Owner modal
* Hide user-dependent actions from posts with no user
* Make PostRevisor work with posts with no user
* Ensure posts with no user can be deleted
* discourse-narrative-bot should ignore posts with no user
* Skip TopicLink creation for posts with no user
When a user accepts an invite with an email address that matches a group
which automatically awards its members Trust Level 2, a race condition might happen
when the 'send_advanced_tutorial_message' job runs.
That job is enqueued inside the 'user_promoted' event which is triggered inside a
transaction on the user record. If the job runs before the transaction is done,
the user record is invisible and this generates an exception.
FileHelper.download requires a string not a URI. I also found another
instance of using open-uri directly and swapped it out to use
FileHelper.
I also updated it to not `read` a file if it comes back nil.
Follow up to: fe01099a38
By requiring open-uri this will fix the following error:
```
NoMethodError (private method `open' called for #<URI::Generic...
```
also switched to the shorter syntax and removed default options. Since
ruby 2.4 redirect is on by default.
To eliminate a DDOS attack vector, we're taking the following measures:
The endpoint will be rate-limited to 3 requests every 60 seconds (per user).
A 24 hours max-age cache header is sent with the response.
The route will be hijacked to generate the certificate in the background.
This reduces chances of errors where consumers of strings mutate inputs
and reduces memory usage of the app.
Test suite passes now, but there may be some stuff left, so we will run
a few sites on a branch prior to merging
