Bootstrapping from Genesis file

[Wondertan]

Currently, the node(go-header) requires a genesis hash of a network for the node to start. However, this Genesis hash is a hash of the first block rather than a Genesis file. This requires the core network to be started first to generate the first block and only after the DA network. Even more, it requires network to be started before we can do a proper release with hardcoded genesis.

To solve this problem, I propose to enable bootstrapping DA nodes from the genesis file:

• Make genesis hash to be the hash of the genesis file, s.t nodes fetch it during initialisation instead.
  • BN would fetch it from Core(may require implementing such API) and circulate it further over DA network in the form of genesis(height 0) Header
  • This assumes that genesis hash contains enough information to attest validity of header/block height 1
• In case genesis file is provided, just use it instead of relying on hash and fetching it

Some questions:

• Does Core provides an API to get genesis by hash?
• Are there utils to assemble genesis and compute its hash without starting a Core node?

Once questions are answered and the solution is implemented, we will be able to run both nodes of both networks independently with a pre-prepared genesis file

[Wondertan]

Cc @liamsi