Use cached address values more often

arma said in #20423 (moved):

Once we get this one in, we might in 0.3.0 consider changing many more of these calls to cache_only=1. In fact, if we leave check_descriptor_ipaddress_changed() calling resolve_my_address() once a minute, maybe we're all set and the whole of router_pick_published_address() can just look at the cached values? I didn't want to make an invasive change like that in 0.2.9 though, since there are probably edge cases we care about, e.g. where getinfo_helper_misc() calls router_pick_published_address() and we're not a relay so we've never called resolve_my_address() before that very moment.