restore the set noder certificate without sudo

[muhamadazmy]

Description

this PR only restore a function that was remove before. It used to use sudo but we don't need sudo for it anymore but we still need the function

[renauter]

Great!
Just to remind that only allowed certifiers can call set_node_certification():

tfchain/substrate-node/pallets/pallet-tfgrid/src/lib.rs

Line 850 in 8dfb941

if !AllowedNodeCertifiers::<T>::get()

Such allowed certifiers that can be added by council approval.
If this is the intention we are all good and we can merge.

[sameh-farouk]

Such allowed certifiers that can be added by council approval.
If this is the intention we are all good and we can merge.

Yes, I believe this issue dealing with this