This change ensures TransitionState.Copy preserves BaseRoot. During a
Verkle transition, ts.BaseRoot is required to construct the overlay MPT
when ts.InTransition() is true. Previously, copies dropped BaseRoot,
risking an invalid zero-hash base trie and inconsistent behavior.
This is the first part of #31532
It maintains a series of conversion maker which are to be updated by the
conversion code (in a follow-up PR, this is a breakdown of a larger PR
to make things easier to review). They can be used in this way:
- During the conversion, by storing the conversion markers when the
block has been processed. This is meant to be written in a function that
isn't currently present, hence [this
TODO](https://github.com/ethereum/go-ethereum/pull/31634/files#diff-89272f61e115723833d498a0acbe59fa2286e3dc7276a676a7f7816f21e248b7R384).
Part of https://github.com/ethereum/go-ethereum/issues/31583
---------
Signed-off-by: Guillaume Ballet <3272758+gballet@users.noreply.github.com>
Co-authored-by: Gary Rong <garyrong0905@gmail.com>
