[esock|test] Add sendmsg/recvmsg medium ping-pong test case for local (stream)
[esock|test] Add sendmsg/recvmsg medium ping-pong test case for local (stream)

Add a sendmsg and recvmsg medium ping-pong test case for
Unix Domain (stream) socket.

OTP-15822

emacsmirror/erlang,uabboli/otp,lrascao/otp,lrascao/otp,dumbbell/otp,aboroska/otp,g-andrade/otp,dumbbell/otp,getong/otp,dumbbell/otp,vladdu/otp,getong/otp,isvilen/otp,getong/otp,electricimp/otp,jj1bdx/otp,getong/otp,vladdu/otp,getong/otp,aboroska/otp,erlang/otp,dumbbell/otp,g-andrade/otp,electricimp/otp,kvakvs/otp,isvilen/otp,kvakvs/otp,bjorng/otp,vladdu/otp,lrascao/otp,bjorng/otp,lrascao/otp,g-andrade/otp,lrascao/otp,vinoski/otp,mikpe/otp,mikpe/otp,aboroska/otp,rlipscombe/otp,uabboli/otp,erlang/otp,isvilen/otp,jj1bdx/otp,g-andrade/otp,legoscia/otp,potatosalad/otp,bjorng/otp,potatosalad/otp,erlang/otp,g-andrade/otp,bjorng/otp,rlipscombe/otp,uabboli/otp,legoscia/otp,mikpe/otp,isvilen/otp,dumbbell/otp,legoscia/otp,ferd/otp,isvilen/otp,jj1bdx/otp,rlipscombe/otp,kvakvs/otp,electricimp/otp,vinoski/otp,mikpe/otp,kvakvs/otp,bjorng/otp,jj1bdx/otp,aboroska/otp,g-andrade/otp,dgud/otp,potatosalad/otp,dgud/otp,bjorng/otp,vinoski/otp,g-andrade/otp,potatosalad/otp,aboroska/otp,jj1bdx/otp,RoadRunnr/otp,mikpe/otp,g-andrade/otp,electricimp/otp,isvilen/otp,erlang/otp,potatosalad/otp,electricimp/otp,emacsmirror/erlang,potatosalad/otp,getong/otp,uabboli/otp,rlipscombe/otp,erlang/otp,dumbbell/otp,RoadRunnr/otp,dgud/otp,rlipscombe/otp,getong/otp,vladdu/otp,potatosalad/otp,ferd/otp,vladdu/otp,kvakvs/otp,jj1bdx/otp,jj1bdx/otp,mikpe/otp,getong/otp,getong/otp,aboroska/otp,emacsmirror/erlang,vinoski/otp,mikpe/otp,potatosalad/otp,vinoski/otp,isvilen/otp,vladdu/otp,RoadRunnr/otp,emacsmirror/erlang,erlang/otp,legoscia/otp,rlipscombe/otp,legoscia/otp,emacsmirror/erlang,rlipscombe/otp,dumbbell/otp,lrascao/otp,vinoski/otp,dgud/otp,electricimp/otp,jj1bdx/otp,aboroska/otp,potatosalad/otp,kvakvs/otp,uabboli/otp,RoadRunnr/otp,legoscia/otp,emacsmirror/erlang,isvilen/otp,jj1bdx/otp,bjorng/otp,aboroska/otp,erlang/otp,emacsmirror/erlang,g-andrade/otp,kvakvs/otp,isvilen/otp,bjorng/otp,uabboli/otp,vladdu/otp,ferd/otp,dgud/otp,g-andrade/otp,isvilen/otp,uabboli/otp,dgud/otp,potatosalad/otp,dgud/otp,electricimp/otp,mikpe/otp,RoadRunnr/otp,RoadRunnr/otp,aboroska/otp,legoscia/otp,RoadRunnr/otp,rlipscombe/otp,getong/otp,dumbbell/otp,ferd/otp,RoadRunnr/otp,electricimp/otp,erlang/otp,bjorng/otp,ferd/otp,ferd/otp,uabboli/otp,ferd/otp,mikpe/otp,mikpe/otp,bjorng/otp,ferd/otp,emacsmirror/erlang,lrascao/otp,kvakvs/otp,vinoski/otp,legoscia/otp,legoscia/otp,RoadRunnr/otp,lrascao/otp,dgud/otp,erlang/otp,rlipscombe/otp,vladdu/otp,emacsmirror/erlang,dgud/otp,uabboli/otp,vinoski/otp,dumbbell/otp,kvakvs/otp,lrascao/otp,rlipscombe/otp,jj1bdx/otp,dumbbell/otp,ferd/otp,dgud/otp,erlang/otp,vinoski/otp,electricimp/otp,vladdu/otp,emacsmirror/erlang,vinoski/otp