ByronSpec integration: don't take SoftwareVersion/ProtocolVersion/key from genesis/ledger

[edsko]

At the moment, the ByronSpec integration

• chooses the protocol version from the ledger state during block production (forgeByronSpecBlock),
• chooses a key from the initial genesis delegates in setup (protocolInfoDualByron)

Instead, we should be able to "boot up a ByronSpec node" with a delegated key, and with different protocol/software version. This will be essential if we want to test block production with update proposals/votes and delegation certificates. When those are posted, nodes would need to be (emulated to be) restarted with new keys/software versions in order to make progress.

[nfrisby]

Seems relevant:

As described in IntersectMBO/cardano-ledger#731 (more context at IntersectMBO/ouroboros-network#1514 (comment) ), the ProtocolVersion field in the Byron header does not describe the protocol version being used by the node, it instead specifies which proposed protocol version number the node is trying to "endorse" (endorsing is -- roughly -- a second round of voting).

And described in Issue #706, the SoftwareVersion field in the header is apparently unused.

[edsko]

Yes, this will we important for the DualLedger tests.

[edsko]

This will only become relevant if we start testing the dual ledger with all transactions. It would be great to do that, but we might well run out of time for Byron testing and have to move on to Shelley testing. Giving this a medium priority.

[dnadales]

@nfrisby is this issue still relevant?