digital/io-hub: rename element to element_type where appropriated
digital/io-hub: handle clamp locking

When the clamp is in a bay with an element at the middle level, it can no
longer move.
digital/io-hub: handle new elements when clamp locked
digital/io-hub: add missing comment
digital/io-hub: add door/clamp command
digital/avr/modules/devices/usdist: new US sensor module
digital/io-hub: add US distance sensors
digital/{io,io-hub,ai}: add generic radar, add radar to robospierre
digital/mimot: default to unlimited motor
digital/ai/tools: use new door and clamp command
digital/io-hub: handle clamp open/close offset
digital/io-hub: add stub path module
digital/io-hub: add move FSM
digital/io-hub: add element score computation
digital/io-hub: add function to get nearest element id and add test_element
digital/io-hub: add function to get position from element id

This is useful to indicate an angle when we want to approach an element the
green zone.
digital/io: fixed how to deduce elements on intersections
digital/{ai,io-hub}: move events
digital/ai/src/fsm: fix timeout assignment
digital/io-hub: fix hardware offset when going to front