Extend slot start message and default status bar with information about
current head fork and the next fork transition (corresponding to head).
This is useful to know whether a synced client is aware of a future fork
and can also be useful when syncing from old forks to follow progress
across the various forks.
```
peers: 8 ❯ finalized: 741c2ce2:230474 ❯ head: b330f58b:230477:20 ❯ fork: Capella (next: Deneb:231680) ❯ time: 230599:24 (7379192) ❯ sync: 00h24m (99.63%) 2.6492slots/s (QwQUwQPQDQ:7375263)/opt
```
```
INF 2024-01-12 12:18:00.001+01:00 Slot start topics="beacnde" slot=7379190 epoch=230599 fork="Capella (next: Deneb:231680)" sync="--h--m (99.62%) 0.0000slots/s (wwwwwwwwww:7375167)/opt" peers=0 head=741c2ce2:7375168 finalized=230472:723abe7e delay=1ms861us
```
As followup from #5654, ensure that we still keep the comment around
referring to the correct `forkchoiceUpdated` to use being driven by
the fork schedule.
* use `PayloadAttributesV3` in `nimbus_light_client` for Deneb
From Deneb onward, `forkchoiceUpdated` requires `PayloadAttributesV3`.
In `nimbus_light_client` we still used `PayloadAttributesV2`.
Also clean up two other locations that were already correctly using
`PayloadAttributesV3`, to reduce code duplication.
* fix letter case
Replace sections that need to be maintained with every `ConsensusFork`
related to LC data collection with a generic logic that keeps working
when unrelated parts of Ethereum change.
The templates for `BeaconBlock`, `BeaconBlockBody` and `BeaconState`
are the only ones using a `macro` mechanism for code generation.
This prevents using the dot-syntax style `consensusFork.BeaconFoo`
in some situations, and also tends to trigger naming conflicts,
requiring the `Type` suffix. Furthermore, the `macro` only works
for types that are re-defined in every single `ConsensusFork`.
Replacing with the simpler but more verbose approach used for other
types for consistency and to avoid the downsides of the `macro`.
Furthermore, simplify `test_fixture_sanity_blocks` to use `forks` sugar.
For symmetry with `forkyState` when using `withState`, and to avoid
problems with shadowing of `blck` when using `withBlck` in `template`,
also rename the injected `blck` to `forkyBlck`.
- https://github.com/nim-lang/Nim/issues/22698
* Add metadata for the Holesky network
* Add copyright banner to the new Nim module
* Working version
* Bump Chronos to fix downloading from Github
* Add checksum check of the downloaded file
* Clean up debugging code and obsolete imports