HTTP endpoints cleanup (#13251)

* remove validation package

* structs cleanup

* merge with apimiddleware removal

* more validation and Bls capitalization

* builder test fix

* use strconv for uint->str conversions

* use DecodeHexWithLength

* use exact param names

* rename http package to httputil

* change conversions to fmt.Sprintf

* handle query paramsd and route variables

* spans and receiver name

* split structs, move bytes helper

* missing ok check

* fix reference to indexed failure

* errors fixup

* add godoc to helper

* fix BLS casing and chainhead ref

* review

* fix import in tests

* gzl

container/slice/slice.go

@@ -1,6 +1,7 @@
 package slice
 
 import (
+	"fmt"
 	"strings"
 
 	"github.com/prysmaticlabs/prysm/v4/consensus-types/primitives"
@@ -391,3 +392,12 @@ func Reverse[E any](s []E) []E {
 	}
 	return s
 }
+
+// VerifyMaxLength takes a slice and a maximum length and validates the length.
+func VerifyMaxLength[T any](v []T, max int) error {
+	l := len(v)
+	if l > max {
+		return fmt.Errorf("length of %d exceeds max of %d", l, max)
+	}
+	return nil
+}