Merge branch 'from/upstream-develop/tusooa/translate-pages' into 'develop'

Translate backend-rendered pages

See merge request pleroma/pleroma!3634

priv/repo/migrations/20220302013920_add_language_to_users.exs

@@ -0,0 +1,9 @@
+defmodule Pleroma.Repo.Migrations.AddLanguageToUsers do
+  use Ecto.Migration
+
+  def change do
+    alter table(:users) do
+      add_if_not_exists(:language, :string)
+    end
+  end
+end