* Add API endpoint to count statuses of all validators (#3756)
* Delete DB schema migrations for v11 and earlier (#3761)
Co-authored-by: Mac L <mjladson@pm.me>
Co-authored-by: Michael Sproul <michael@sigmaprime.io>
## Issue Addressed
Closes https://github.com/sigp/lighthouse/issues/2327
## Proposed Changes
This is an extension of some ideas I implemented while working on `tree-states`:
- Cache the indexed attestations from blocks in the `ConsensusContext`. Previously we were re-computing them 3-4 times over.
- Clean up `import_block` by splitting each part into `import_block_XXX`.
- Move some stuff off hot paths, specifically:
- Relocate non-essential tasks that were running between receiving the payload verification status and priming the early attester cache. These tasks are moved after the cache priming:
- Attestation observation
- Validator monitor updates
- Slasher updates
- Updating the shuffling cache
- Fork choice attestation observation now happens at the end of block verification in parallel with payload verification (this seems to save 5-10ms).
- Payload verification now happens _before_ advancing the pre-state and writing it to disk! States were previously being written eagerly and adding ~20-30ms in front of verifying the execution payload. State catchup also sometimes takes ~500ms if we get a cache miss and need to rebuild the tree hash cache.
The remaining task that's taking substantial time (~20ms) is importing the block to fork choice. I _think_ this is because of pull-tips, and we should be able to optimise it out with a clever total active balance cache in the state (which would be computed in parallel with payload verification). I've decided to leave that for future work though. For now it can be observed via the new `beacon_block_processing_post_exec_pre_attestable_seconds` metric.
Co-authored-by: Michael Sproul <micsproul@gmail.com>
## Issue Addressed
our bootnodes as of now support only ipv4. this makes it so that they support ipv6
## Proposed Changes
- Adds code necessary to update the bootnodes to run on dual stack nodes and therefore contact and store ipv6 nodes.
- Adds some metrics about connectivity type of stored peers. It might have been nice to see some metrics over the sessions but that feels out of scope right now.
## Additional Info
- some code quality improvements sneaked in since the changes seemed small
- I think it depends on the OS, but enabling mapped addresses on an ipv6 node without dual stack support enabled could fail silently, making these nodes effectively ipv6 only. In the future I'll probably change this to use two sockets, which should fail loudly
