Find out if we need to optimise node_get_all_orports()
From #3786 (moved):
If node_get_all_orports() is at all near the critical path, we should think about some way to
make it faster: allocating and freeing little objects over and over can get expensive.
Would you suggest node_get_all_orports() taking a smartlist pointer as an argument? And even two (optional) tor_addr_t pointers?