Keyword/phrase filtering (#7905)

* Add keyword filtering

    GET|POST       /api/v1/filters
    GET|PUT|DELETE /api/v1/filters/:id

- Irreversible filters can drop toots from home or notifications
- Other filters can hide toots through the client app
- Filters use a phrase valid in particular contexts, expiration

* Make sure expired filters don't get applied client-side

* Add missing API methods

* Remove "regex filter" from column settings

* Add tests

* Add test for FeedManager

* Add CustomFilter test

* Add UI for managing filters

* Add streaming API event to allow syncing filters

* Fix tests

app/models/invite.rb

@@ -15,33 +15,19 @@
 #
 
 class Invite < ApplicationRecord
+  include Expireable
+
   belongs_to :user
   has_many :users, inverse_of: :invite
 
   scope :available, -> { where(expires_at: nil).or(where('expires_at >= ?', Time.now.utc)) }
-  scope :expired, -> { where.not(expires_at: nil).where('expires_at < ?', Time.now.utc) }
 
   before_validation :set_code
 
-  attr_reader :expires_in
-
-  def expires_in=(interval)
-    self.expires_at = interval.to_i.seconds.from_now unless interval.blank?
-    @expires_in     = interval
-  end
-
   def valid_for_use?
     (max_uses.nil? || uses < max_uses) && !expired?
   end
 
-  def expire!
-    touch(:expires_at)
-  end
-
-  def expired?
-    !expires_at.nil? && expires_at < Time.now.utc
-  end
-
   private
 
   def set_code