Linkmgrd monitors link status, mux status, and link state. Has
the link becomes unhealthy, linkmgrd will trigger mux switchover
on a standby ToR ensuring uninterrupted service to servers/blades.
This PR is initial implementation of linkmgrd.
Also, docker-mux container hold packages related to maintaining and managing
mux cable. It currently runs linkmgrd binary that monitor and switches
the mux if needed.
This PR also introduces mux-container and starts linkmgrd as startup when
build is configured with INCLUDE_MUX=y
Edit: linkmgrd PR will follow.
signed-off-by: Tamer Ahmed <tamer.ahmed@microsoft.com>
Related work items: #2315, #3146150
