Change language opt-out to language opt-in (#7823)

* Switch filtered_languages to chosen_languages

* Adjust interface

* Remove unused translations

app/models/account.rb

@@ -141,7 +141,7 @@ class Account < ApplicationRecord
            prefix: true,
            allow_nil: true
 
-  delegate :filtered_languages, to: :user, prefix: false, allow_nil: true
+  delegate :chosen_languages, to: :user, prefix: false, allow_nil: true
 
   def local?
     domain.nil?

app/models/status.rb

@@ -190,8 +190,8 @@ class Status < ApplicationRecord
   before_validation :set_local
 
   class << self
-    def not_in_filtered_languages(account)
-      where(language: nil).or where.not(language: account.filtered_languages)
+    def in_chosen_languages(account)
+      where(language: nil).or where(language: account.chosen_languages)
     end
 
     def as_home_timeline(account)
@@ -333,7 +333,7 @@ class Status < ApplicationRecord
     def filter_timeline_for_account(query, account, local_only)
       query = query.not_excluded_by_account(account)
       query = query.not_domain_blocked_by_account(account) unless local_only
-      query = query.not_in_filtered_languages(account) if account.filtered_languages.present?
+      query = query.in_chosen_languages(account) if account.chosen_languages.present?
       query.merge(account_silencing_filter(account))
     end
 

app/models/user.rb

@@ -35,6 +35,7 @@
 #  moderator                 :boolean          default(FALSE), not null
 #  invite_id                 :bigint(8)
 #  remember_token            :string
+#  chosen_languages          :string           is an Array
 #
 
 class User < ApplicationRecord
@@ -317,7 +318,9 @@ class User < ApplicationRecord
   private
 
   def sanitize_languages
-    filtered_languages.reject!(&:blank?)
+    return if chosen_languages.nil?
+    chosen_languages.reject!(&:blank?)
+    self.chosen_languages = nil if chosen_languages.empty?
   end
 
   def prepare_new_user!