Define and use `CONST_TO_FOO_CONN()`
We frequently do this:
const connection_t *conn = ...; const or_connection_t *or_conn = TO_OR_CONN((connection_t*)conn);
Instead let's define a CONST_TO_OR_CONN() variant, like we have for circuits. We can do similar for the other connection types.
To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information