This Pr implements some prerequisite changes for #34004 : split the
`CachingDB` into a `MerkleDB` and a `UBTDB`, so that very different
behaviors don't clash as much.
The transition isn't handled by this PR, but after talking to Gary we
agreed that `UBTDB` should receive another `triedb`, which will only be
loaded if the `Ended` flag is set to false in the conversion contract.
If this is too hard to achieve, it makes sense to load it regardless,
and then loading can be prevented at a later stage by adding a
`UBTTransitionFinalizationTime` in `ChainConfig`.
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Co-authored-by: Gary Rong <garyrong0905@gmail.com>
This is broken off of #31730 to only focus on testing networks that
start with verkle at genesis.
The PR has seen a lot of work since its creation, and it now targets
creating and re-executing tests for a binary tree testnet without the
transition (so it starts at genesis). The transition tree has been moved
to its own package. It also replaces verkle with the binary tree for
this specific application.
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Co-authored-by: Gary Rong <garyrong0905@gmail.com>
