feat: add RESEND packet handler

chore: change debug logs and add comment

bug: clarify sdtp_packet_*_entry mbuf layout

test: add packet drop hook for integration tests

feat: implement prototype to handle NEED_ACK packets

feat: add sysctl metrics for packet type received

chore: remove SDTP_STATIC

bug: lock bucket when thread doesn't own RPC or it is different lock

chore: move sdtp_local_id() to common header

bug: account for hashmap and interest references in RPC lifetime

chore: add all RPCs debug log to receive path

bug: rely on RPC refs during reap

bug: free peer if nh_object lookup fails

feat: add RPC refs count assertion

feat: add reference counting and deallocation to SDTP peers