Tight subobject bounds in sockaddr_* structs in Netgraph and Bluetooth HCI subsystem

[RoundofThree]

• Type: Unneeded subobject bounds causes CHERI bounds violation
• Trigger Conditions: Unprivileged BLUETOOTH_PROTO_HCI socket or unprivileged AF_NETGRAPH socket
• Impact: Local DoS on CheriBSD only.
• Root cause:
  Any socket operation that casts sockaddr to sockaddr_ng or sockaddr_hci will lead to a capability bounds fault, for example, ng_btsocket_hci_raw_bind or ng_btsocket_hci_raw_sockaddr.