* Exclude some storage tests
why:
These test running on external dumps slipped through. The particular
dumps were reported earlier as somehow dodgy.
This was changed in `#1457` but having a second look, the change on
hexary_interpolate.nim(350) might be incorrect.
* Redesign `Aristo DB` descriptor for transaction based layers
why:
Previous descriptor layout made it cumbersome to push/pop
database delta layers.
The new architecture keeps each layer with the full delta set
relative to the database backend.
* Keep root ID as part of the `Patricia Trie` leaf path
why;
That way, forests are supported
* Keep vertex ID generator state with each db-layer
why:
The vertex ID generator state is part of the difference to the below
layer
* Move otherwise unused source to test directory
* Add Merkle hash generator
also:
* Verification facility for debugging
* Empty Merkle key hashes encoded as `EMPTY_ROOT_HASH`
* Cosmetics, renamed fields (eVtx, bVtx) -> (eVid, bVid)
* Multilayered delta architecture for Aristo DB
details:
Any VertexID or data retrieval needs to go down the rabbit hole and
fetch/get/manipulate the bottom layer -- even without explicit
backend.
* Direct reference to backend from top-level layer
why:
Some services as the vid management needs to be synchronised among all
layers. So access is optimised.