* Nimbus folder environment update
details:
* Integrated `CoreDbRef` for the sources in the `nimbus` sub-folder.
* The `nimbus` program does not compile yet as it needs the updates
in the parallel `stateless` sub-folder.
* Stateless environment update
details:
* Integrated `CoreDbRef` for the sources in the `stateless` sub-folder.
* The `nimbus` program compiles now.
* Premix environment update
details:
* Integrated `CoreDbRef` for the sources in the `premix` sub-folder.
* Fluffy environment update
details:
* Integrated `CoreDbRef` for the sources in the `fluffy` sub-folder.
* Tools environment update
details:
* Integrated `CoreDbRef` for the sources in the `tools` sub-folder.
* Nodocker environment update
details:
* Integrated `CoreDbRef` for the sources in the
`hive_integration/nodocker` sub-folder.
* Tests environment update
details:
* Integrated `CoreDbRef` for the sources in the `tests` sub-folder.
* The unit tests compile and run cleanly now.
* Generalise `CoreDbRef` to any `select_backend` supported database
why:
Generalisation was just missed due to overcoming some compiler oddity
which was tied to rocksdb for testing.
* Suppress compiler warning for `newChainDB()`
why:
Warning was added to this function which must be wrapped so that
any `CatchableError` is re-raised as `Defect`.
* Split off persistent `CoreDbRef` constructor into separate file
why:
This allows to compile a memory only database version without linking
the backend library.
* Use memory `CoreDbRef` database by default
detail:
Persistent DB constructor needs to import `db/core_db/persistent
why:
Most tests use memory DB anyway. This avoids linking `-lrocksdb` or
any other backend by default.
* fix `toLegacyBackend()` availability check
why:
got garbled after memory/persistent split.
* Clarify raw access to MPT for snap sync handler
why:
Logically, `kvt` is not the raw access for the hexary trie (although
this holds for the legacy database)
221e6c9e2f