MNT/API: rename is_moving -> moving
MNT/API: rename is_moving -> moving

Work with the existing ophyd API as much as possible

sameera2004/bluesky,klauer/bluesky,ericdill/bluesky,sameera2004/bluesky,dchabot/bluesky,ericdill/bluesky,dchabot/bluesky,klauer/bluesky