This PR causes a few new warnings to appear - these are harmless but
will need addressing separately as they span several libraries.
* new asyncraises syntax
* asyncraises support in several modules
* `sink` usage reduces spurious copying
* `?` compatiblity for `async` + `results`
* remove `-d:chronosStrictException` (obsolete)
Some upstream repos still need fixes, but this gets us close enough that
style hints can be enabled by default.
In general, "canonical" spellings are preferred even if they violate
nep-1 - this applies in particular to spec-related stuff like
`genesis_validators_root` which appears throughout the codebase.
Introduced in #3171, it turns out we can just follow the block headers
to achieve the same effect
* leaves the constant in the code so as to avoid confusion when reading
database that had the constant written (such as the fleet nodes and
other unstable users)
