* Rename BeaconStateMerge to BeaconStateBellatrix
* Rename version.Merge to version.Bellatrix
* Rename ComputeFieldRootsWithHasherMerge to ComputeFieldRootsWithHasherBellatrix
* Rename test names to Bellatrix
* Rename comments and strings to Bellatrix
* Fix formatting in a few files
* Revert wrong renaming in test name
* Revert renaming to Bellatrix in mainnet_config.go
* Revert renaming of db key without migration
* Regenerate from proto changes
* Rename new use of already renamed symbols
* gofmt and goimports after regenerating protofiles
* revert weird imports
Co-authored-by: prestonvanloon <preston@prysmaticlabs.com>