Change ByID boolean to Peer string and add Peer id in replicas output

The CLI will now be able to display the peer IDs in MetaGroupInfo
if it choses to do so, and possibly help user select the peer ID
from a list with a new command to remove by peer ID instead of
by server name.

Signed-off-by: Ivan Kozlovic <ivan@synadia.com>

server/jetstream_api.go

@@ -581,7 +581,9 @@ const JSApiLeaderStepDownResponseType = "io.nats.jetstream.api.v1.meta_leader_st
 type JSApiMetaServerRemoveRequest struct {
 	// Server name of the peer to be removed.
 	Server string `json:"peer"`
-	ByID   bool   `json:"by_id,omitempty"`
+	// Peer ID of the peer to be removed. If specified this is used
+	// instead of the server name.
+	Peer string `json:"peer_id,omitempty"`
 }
 
 // JSApiMetaServerRemoveResponse is the response to a peer removal request in the meta group.
@@ -2216,9 +2218,10 @@ func (s *Server) jsLeaderServerRemoveRequest(sub *subscription, c *client, _ *Ac
 	var found string
 	js.mu.RLock()
 	for _, p := range cc.meta.Peers() {
-		if req.ByID {
-			if p.ID == req.Server {
-				found = req.Server
+		// If Peer is specified, it takes precedence
+		if req.Peer != _EMPTY_ {
+			if p.ID == req.Peer {
+				found = req.Peer
 				break
 			}
 			continue