## Issue Addressed
NA
## Proposed Changes
- Refactor the `bls` crate to support multiple BLS "backends" (e.g., milagro, blst, etc).
- Removes some duplicate, unused code in `common/rest_types/src/validator.rs`.
- Removes the old "upgrade legacy keypairs" functionality (these were unencrypted keys that haven't been supported for a few testnets, no one should be using them anymore).
## Additional Info
Most of the files changed are just inconsequential changes to function names.
## TODO
- [x] Optimization levels
- [x] Infinity point: https://github.com/supranational/blst/issues/11
- [x] Ensure milagro *and* blst are tested via CI
- [x] What to do with unsafe code?
- [x] Test infinity point in signature sets
* Layer do_atomically() abstractions properly
* Reduce allocs and DRY get_key_for_col()
* Parameterize HotColdDB with hot and cold item stores
* -impl Store for MemoryStore
* Replace Store uses with HotColdDB
* Ditch Store trait
* cargo fmt
* Style fix
* Readd missing dep that broke the build
* Add PH & MS slot clock changes
* Account for genesis time
* Add progress on duties refactor
* Add simple is_aggregator bool to val subscription
* Start work on attestation_verification.rs
* Add progress on ObservedAttestations
* Progress with ObservedAttestations
* Fix tests
* Add observed attestations to the beacon chain
* Add attestation observation to processing code
* Add progress on attestation verification
* Add first draft of ObservedAttesters
* Add more tests
* Add observed attesters to beacon chain
* Add observers to attestation processing
* Add more attestation verification
* Create ObservedAggregators map
* Remove commented-out code
* Add observed aggregators into chain
* Add progress
* Finish adding features to attestation verification
* Ensure beacon chain compiles
* Link attn verification into chain
* Integrate new attn verification in chain
* Remove old attestation processing code
* Start trying to fix beacon_chain tests
* Split adding into pools into two functions
* Add aggregation to harness
* Get test harness working again
* Adjust the number of aggregators for test harness
* Fix edge-case in harness
* Integrate new attn processing in network
* Fix compile bug in validator_client
* Update validator API endpoints
* Fix aggreagation in test harness
* Fix enum thing
* Fix attestation observation bug:
* Patch failing API tests
* Start adding comments to attestation verification
* Remove unused attestation field
* Unify "is block known" logic
* Update comments
* Supress fork choice errors for network processing
* Add todos
* Tidy
* Add gossip attn tests
* Disallow test harness to produce old attns
* Comment out in-progress tests
* Partially address pruning tests
* Fix failing store test
* Add aggregate tests
* Add comments about which spec conditions we check
* Dont re-aggregate
* Split apart test harness attn production
* Fix compile error in network
* Make progress on commented-out test
* Fix skipping attestation test
* Add fork choice verification tests
* Tidy attn tests, remove dead code
* Remove some accidentally added code
* Fix clippy lint
* Rename test file
* Add block tests, add cheap block proposer check
* Rename block testing file
* Add observed_block_producers
* Tidy
* Switch around block signature verification
* Finish block testing
* Remove gossip from signature tests
* First pass of self review
* Fix deviation in spec
* Update test spec tags
* Start moving over to hashset
* Finish moving observed attesters to hashmap
* Move aggregation pool over to hashmap
* Make fc attn borrow again
* Fix rest_api compile error
* Fix missing comments
* Fix monster test
* Uncomment increasing slots test
* Address remaining comments
* Remove unsafe, use cfg test
* Remove cfg test flag
* Fix dodgy comment
* Ignore aggregates that are already known.
* Unify aggregator modulo logic
* Fix typo in logs
* Refactor validator subscription logic
* Avoid reproducing selection proof
* Skip HTTP call if no subscriptions
* Rename DutyAndState -> DutyAndProof
* Tidy logs
* Print root as dbg
* Fix compile errors in tests
* Fix compile error in test
