Make Custom command module available for Virtualmin virtualservers

Very often Virtualmin virtualservers needs to execute custom commands, for example "Change owner of files in virtualserver directory". At now there are exists Webmin Custom command module, but it is not integrated in Virtualmin, so we can't operate in it with current virtualserver info, such as owner, home directory, etc. And it is located in Webmin tab, so not easy searchable for Virtualserver owners.

Please make "Custom commands" menu in Virtualserver with ability to add custom commands for each virtualserver.