Hardware tree addressing system

Summary

Add classes or functions to fetch nodes from the hardware tree using their "address". This heavily depends on #43 (closed), but hopefully most of it can be abstracted away into shared algorithms.

marked this issue as related to #8 (closed)

marked this issue as related to #43 (closed)

assigned to @lmoureau

added 1 deleted label

mentioned in merge request !35 (merged)

added doing label

closed with merge request !35 (merged)

mentioned in commit 04a048b3