* Revert "Revert "Update fastssz" (#7100)"
This reverts commit b954db9704.
* Preston's patch
* Merge branch 'master' of github.com:prysmaticlabs/prysm into revert-7100-revert-6760-update-fssz
* Update fssz, add regression test case
* more HTR with fssz
* fix some tests
* only one test left
* Make it so that HTR will work
* gofmt, imports
* gofmt, imports
* fix
* Merge branch 'master' of github.com:prysmaticlabs/prysm into revert-7100-revert-6760-update-fssz
* fix
* Merge branch 'master' into revert-7100-revert-6760-update-fssz
* Merge refs/heads/master into revert-7100-revert-6760-update-fssz
* gaz
* Merge branch 'revert-7100-revert-6760-update-fssz' of github.com:prysmaticlabs/prysm into revert-7100-revert-6760-update-fssz
* Merge refs/heads/master into revert-7100-revert-6760-update-fssz
* fix test
* Merge branch 'revert-7100-revert-6760-update-fssz' of github.com:prysmaticlabs/prysm into revert-7100-revert-6760-update-fssz
* Merge refs/heads/master into revert-7100-revert-6760-update-fssz
* add more tests
* gaz
* Merge refs/heads/master into addBLSMethods
* Merge refs/heads/master into addBLSMethods
* Merge refs/heads/master into addBLSMethods
* Merge refs/heads/master into addBLSMethods
* refactor BLS to expose an interface rather than a single implementation
* Split up tests, gofmt, goimports, docs
* godoc for signature.Copy()
* more godocs
* revert gomod / deps changes
* rm newline
* revert proto changes
* rename bls12 to herumi for clarity