Fixed size arrays in block interfaces and structs (#11375)

* Fixed size arrays in block fields

* test fix

* fmt

* fix fetcher test

* fix fuzz tests

Co-authored-by: prylabs-bulldozer[bot] <58059840+prylabs-bulldozer[bot]@users.noreply.github.com>

tools/blocktree/BUILD.bazel

@@ -10,7 +10,6 @@ go_library(
         "//beacon-chain/db:go_default_library",
         "//beacon-chain/db/filters:go_default_library",
         "//consensus-types/primitives:go_default_library",
-        "//encoding/bytesutil:go_default_library",
         "@com_github_emicklei_dot//:go_default_library",
     ],
 )

tools/blocktree/main.go

@@ -19,7 +19,6 @@ import (
 	"github.com/prysmaticlabs/prysm/v3/beacon-chain/db"
 	"github.com/prysmaticlabs/prysm/v3/beacon-chain/db/filters"
 	types "github.com/prysmaticlabs/prysm/v3/consensus-types/primitives"
-	"github.com/prysmaticlabs/prysm/v3/encoding/bytesutil"
 )
 
 var (
@@ -86,7 +85,7 @@ func main() {
 
 		dotN := graph.Node(rStr).Box().Attr("label", label)
 		n := &node{
-			parentRoot: bytesutil.ToBytes32(b.Block().ParentRoot()),
+			parentRoot: b.Block().ParentRoot(),
 			dothNode:   &dotN,
 		}
 		m[r] = n