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
Fixes to the quote feature. Most important changes listed below:
* FIX: Correctly attribute quotes when using Reply button
* FIX: Correctly attribute quotes when using replyAsNewTopic
* FIX: Allow quoting a quote
* FIX: Correctly mark quotes as "full"
* FIX: Don't try to create a quote if it's empty
* DEV: Remove an obsolete method `loadQuote`
It isn't used in core anymore, the only use in core has been removed over 4 years ago in 3251bcb. It's not used in any plugins in all-the-plugins and all references to it on GitHub are from outdated forks (https://github.com/search?q=%22Post.loadQuote%22&type=Code)
