LACP: Link protection

This feature adds support for LACP link protection on aggregated Ethernet interfaces, including revertive operation, member-link port priority, fast failover, and manual switchover between active and standby links. Port priority determines which member link is preferred for active use, with lower values indicating higher priority. Revertive mode enables traffic to return to the preferred higher-priority link when it becomes available. Fast failover allows traffic received on standby links to be accepted for quicker convergence after a failure. You can also manually switch traffic between active and standby links using the 'request lacp link-switchover' operational command.