Design network Grid topology

[kishansagathiya]

Issue summary

• Grid Topology sort of determines to whom we are supposed to send some messages and from whom we are supposed to receive them.
• It designs rows and columns for other validators (validators that are neighbours to us)

I will leave rest for @axaysagathiya to add information here. Go over the code link provided and write specification in this issue in terms of what we need as part of this issue.

Other information and links

• https://github.com/paritytech/polkadot-sdk/blob/1617852a2f1caec796f2b218aecae2facaeacad6/polkadot/node/network/protocol/src/grid_topology.rs#L1

[jimjbrettj]

As an additional point to consider, I believe a grid topology will be used in JAMs network too, so extra important to have a modular design here

[kishansagathiya]

@axaysagathiya can you also write why do you need this in statement distribution

[axaysagathiya]

When a para-validator issues its own validity statement about a candidate block, the statement must be circulated to all other para-validators in the group.
To circulate this statement, we need a grid topology protocol.