## 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
* Add logging on shutdown
* Replace tokio::spawn with handle.spawn
* Upgrade tokio
* Add a task executor
* Beacon chain tasks use task executor
* Validator client tasks use task executor
* Rename runtime_handle to executor
* Add duration histograms; minor fixes
* Cleanup
* Fix logs
* Fix tests
* Remove random file
* Get enr dependency instead of libp2p
* Address some review comments
* Libp2p takes a TaskExecutor
* Ugly fix libp2p tests
* Move TaskExecutor to own file
* Upgrade Dockerfile rust version
* Minor fixes
* Revert "Ugly fix libp2p tests"
This reverts commit 58d4bb690f52de28d893943b7504d2d0c6621429.
* Pretty fix libp2p tests
* Add spawn_without_exit; change Counter to Gauge
* Tidy
* Move log from RuntimeContext to TaskExecutor
* Fix errors
* Replace histogram with int_gauge for async tasks
* Fix todo
* Fix memory leak in test by exiting all spawned tasks at the end
