Namespace build configurations of modules, make more things into constexpr
(not fully finished though)
Unify code using ...Count() to parse IDs
Avoid using unsigned char aka uint8_t as index, prefer size_t
as most code already uses it anyway. Making sure we never accidentally
truncate the value or try to read it as 32bit-wide. Also, simplify
access to built in containers, since those use the wide type as well.
Renames led and button types, more consistent initialization and field access.