fix missing meta in resp of getPeers (#15371)

Co-authored-by: james-prysm <90280386+james-prysm@users.noreply.github.com>

api/server/structs/endpoints_node.go

@@ -33,8 +33,14 @@ type GetPeerResponse struct {
 	Data *Peer `json:"data"`
 }
 
+// Added Meta to align with beacon-api: https://ethereum.github.io/beacon-APIs/#/Node/getPeers
+type Meta struct {
+	Count int `json:"count"`
+}
+
 type GetPeersResponse struct {
 	Data []*Peer `json:"data"`
+	Meta Meta    `json:"meta"`
 }
 
 type Peer struct {