Filter on allowed user language preferences (#2361)

* Naive approached to timeline filtering

* Convert allowed_languages into a db column

* Allow users to choose languages to see statuses in

* Style list items as two columns

* Add a hint to explain language filtering preference

app/models/account.rb

@@ -82,6 +82,8 @@ class Account < ApplicationRecord
            prefix: true,
            allow_nil: true
 
+  delegate :allowed_languages, to: :user, prefix: false, allow_nil: true
+
   def follow!(other_account)
     active_relationships.where(target_account: other_account).first_or_create!(target_account: other_account)
   end

app/models/status.rb

@@ -119,6 +119,10 @@ class Status < ApplicationRecord
   end
 
   class << self
+    def in_allowed_languages(account)
+      where(language: account.allowed_languages)
+    end
+
     def as_home_timeline(account)
       where(account: [account] + account.following)
     end
@@ -198,6 +202,7 @@ class Status < ApplicationRecord
 
     def filter_timeline_for_account(query, account)
       query = query.not_excluded_by_account(account)
+      query = query.in_allowed_languages(account) if account.allowed_languages.present?
       query.merge(account_silencing_filter(account))
     end