Documentation link for each item key in the UI

Once ZBX-21790 is completed, we have a way to link to help for each individual item described in "Standard items". It would be really convenient to have a dedicated link near each item description in the item selection dialog:

Also, the "Standard items" popup must have help icon that links to https://www.zabbix.com/documentation/<version>/en/manual/config/items/itemtypes