Merge branch 'pin-chats' into 'develop'

Chats: pin/unpin chats

See merge request pleroma/pleroma!3637

priv/repo/migrations/20220222203933_add_pinned_to_chats.exs

@@ -0,0 +1,11 @@
+defmodule Pleroma.Repo.Migrations.AddPinnedToChats do
+  use Ecto.Migration
+
+  def change do
+    alter table(:chats) do
+      add(:pinned, :boolean, default: false, null: false)
+    end
+
+    create(index(:chats, [:pinned]))
+  end
+end