Change lists to reflect added and removed users retroactively (#32930)

app/services/remove_accounts_from_list_service.rb

@@ -0,0 +1,29 @@
+# frozen_string_literal: true
+
+class RemoveAccountsFromListService < BaseService
+  def call(list, accounts)
+    @list = list
+    @accounts = accounts
+
+    return if @accounts.empty?
+
+    unmerge_from_list!
+    update_list!
+  end
+
+  private
+
+  def update_list!
+    ListAccount.where(list: @list, account: @accounts).destroy_all
+  end
+
+  def unmerge_from_list!
+    UnmergeWorker.push_bulk(unmerge_account_ids) do |account_id|
+      [account_id, @list.id, 'list']
+    end
+  end
+
+  def unmerge_account_ids
+    ListAccount.where(list: @list, account: @accounts).where.not(follow_id: nil).pluck(:account_id)
+  end
+end