LPS-42663 Add missing key SITE_TEAMS_ADMIN to PortletKeys
LPS-42663 Use liferay-portlet:renderURL with proper params to render Site Teams admin portlet from Users portlet

1. The old way leaded to generate "users_admin/edit_team" path, which was not valid.
2. Adding the following <action> element to struts-config.xml

<action path="/users_admin/edit_team" forward="portlet.sites_admin.edit_team" />

doesn't solve this issue, as we have to get through on the EditTeamAction#render method to properly initialize the Edit Team view. Otherwise, we would get 'NoSuchGroupException: No group exists with primary key 0' exception.
LPS-42663 Remove unused struct action
LPS-42811 Remove the direct link from the detail of an Organization to the teams of its site
LPS-42811 SF