Added a Hard Fork event which will enable transaction metadata in Bor

[pratikspatil024]

Transaction metadata will help speed up parallel execution (Block-STM). The block producer will calculate the dependency and put it in the Extra Field in the Block Header.

[pratikspatil024]

Hi @battlmonstr, I am working on Block-STM and I need this function to store transaction dependency (which Block-STM will use) in the Extra field in Bor's block header. This PR does a similar change in Bor.

Therefore I have created this PR. Once this is merged, I'll use this function in the erigon repo and will create a PR there.

For your reference, there is a similar PR.

Thank you.

[battlmonstr]

@pratikspatil024 thanks for explaining. Could you create that erigon PR you plan to do and refer to this one? Whoever reviews the erigon's PR should review and merge both PRs at the same time (adjusting the erigonlib reference). For local development I recommend to add this to go.mod:

replace github.com/ledgerwatch/erigon-lib => ../erigon-lib

(assuming the erigon-lib is cloned to the parent directory of erigon)

this should untie you from having this PR merged first, before working on the erigon's PR

[pratikspatil024]

Thanks, @battlmonstr. Created the PR.

[yperbasis]

@pratikspatil024 Please rebase/merge the latest erigon-lib so that only your own changes are displayed.