All Ubiquity outdoor units already have this features. and you can see attached image for one of these POE units with RST button.
Technically it is very easy but need to add electronic circuit on hardware to detect if two wires (pairs) are short for more than 10 sec. but not Power wires not(4,5,7,8)...assuming 1,2 pairs simply MikroTik hardware team can added simple electronic circuit can detect short between these two pairs and if that short take more than 10 sec this circuit can send rest command to CPU to make outdoor will reset it self . I think ubiquity did same idea.
This is the simplest way but I am sure there is more than one story to make this done.