Implement muting, add it to the mastodon API

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -576,6 +576,18 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
 
   defp restrict_reblogs(query, _), do: query
 
+  defp restrict_muted(query, %{"muting_user" => %User{info: info}}) do
+    mutes = info["mutes"] || []
+
+    from(
+      activity in query,
+      where: fragment("not (? = ANY(?))", activity.actor, ^mutes),
+      where: fragment("not (?->'to' \\?| ?)", activity.data, ^mutes)
+    )
+  end
+
+  defp restrict_muted(query, _), do: query
+
   defp restrict_blocked(query, %{"blocking_user" => %User{info: info}}) do
     blocks = info.blocks || []
     domain_blocks = info.domain_blocks || []
@@ -629,6 +641,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     |> restrict_type(opts)
     |> restrict_favorited_by(opts)
     |> restrict_blocked(opts)
+    |> restrict_muted(opts)
     |> restrict_media(opts)
     |> restrict_visibility(opts)
     |> restrict_replies(opts)