Fix remote reporters not receiving suspend/unsuspend activities (#16050)

app/lib/account_reach_finder.rb

@@ -0,0 +1,25 @@
+# frozen_string_literal: true
+
+class AccountReachFinder
+  def initialize(account)
+    @account = account
+  end
+
+  def inboxes
+    (followers_inboxes + reporters_inboxes + relay_inboxes).uniq
+  end
+
+  private
+
+  def followers_inboxes
+    @account.followers.inboxes
+  end
+
+  def reporters_inboxes
+    Account.where(id: @account.targeted_reports.select(:account_id)).inboxes
+  end
+
+  def relay_inboxes
+    Relay.enabled.pluck(:inbox_url)
+  end
+end