This commit replaces the "enabled" checkbox on the automation page with a
toggle at the top of the automation page. We've made this change to make
the automation edit page consistent with the automations list page where
a toggle is used for turning on/off automations, and also consistent
with the rest of admin pages where we've been using toggle for
controlling the enable/disable state.
Internal topic: t/153523.
Relaxed restrictions:
- Automation posts are not validated for similarity. This was causing
error when PMs were created by regular user with same content and sent
to different users.
- Don't create warning logs when PM target does not exist anymore. When
for example spammer was deleted, delayed PM is not sent, but it is
correct behaviour;
- Allow tags to be applied even if an automation user is not allowed to
tag;
- Restricted category tags should be visible in configuration UI. Still,
they will be applied only when specific topic belongs to correct
category.
The script `send_chat_message` when used with the `post_created_edited` trigger now accepts `{{post_quote}}` as placeholder for the value of `message`.
This is made possible by a new method in `utils`. Usage:
```ruby
placeholders["foo"] = utils.build_quote(post)
```
