pb: add id field to Heartbeat message for stable volume server identification

This adds an 'id' field to the Heartbeat protobuf message that allows
volume servers to identify themselves independently of their IP:port address.

Ref: https://github.com/seaweedfs/seaweedfs/issues/7487

weed/pb/master.proto

@@ -81,6 +81,7 @@ message Heartbeat {
   map<string, uint32> max_volume_counts = 4;
   uint32 grpc_port = 20;
   repeated string location_uuids = 21;
+  string id = 22; // volume server id, independent of ip:port for stable identification
 }
 
 message HeartbeatResponse {

weed/pb/master_pb/master.pb.go

@@ -44,6 +44,7 @@ type Heartbeat struct {
 	MaxVolumeCounts map[string]uint32                  `protobuf:"bytes,4,rep,name=max_volume_counts,json=maxVolumeCounts,proto3" json:"max_volume_counts,omitempty" protobuf_key:"bytes,1,opt,name=key" protobuf_val:"varint,2,opt,name=value"`
 	GrpcPort        uint32                             `protobuf:"varint,20,opt,name=grpc_port,json=grpcPort,proto3" json:"grpc_port,omitempty"`
 	LocationUuids   []string                           `protobuf:"bytes,21,rep,name=location_uuids,json=locationUuids,proto3" json:"location_uuids,omitempty"`
+	Id              string                             `protobuf:"bytes,22,opt,name=id,proto3" json:"id,omitempty"` // volume server id, independent of ip:port for stable identification
 	unknownFields   protoimpl.UnknownFields
 	sizeCache       protoimpl.SizeCache
 }
@@ -204,6 +205,13 @@ func (x *Heartbeat) GetLocationUuids() []string {
 	return nil
 }
 
+func (x *Heartbeat) GetId() string {
+	if x != nil {
+		return x.Id
+	}
+	return ""
+}
+
 type HeartbeatResponse struct {
 	state                  protoimpl.MessageState `protogen:"open.v1"`
 	VolumeSizeLimit        uint64                 `protobuf:"varint,1,opt,name=volume_size_limit,json=volumeSizeLimit,proto3" json:"volume_size_limit,omitempty"`
@@ -4038,7 +4046,7 @@ var File_master_proto protoreflect.FileDescriptor
 
 const file_master_proto_rawDesc = "" +
 	"\n" +
-	"\fmaster.proto\x12\tmaster_pb\"\xc0\a\n" +
+	"\fmaster.proto\x12\tmaster_pb\"\xd0\a\n" +
 	"\tHeartbeat\x12\x0e\n" +
 	"\x02ip\x18\x01 \x01(\tR\x02ip\x12\x12\n" +
 	"\x04port\x18\x02 \x01(\rR\x04port\x12\x1d\n" +
@@ -4063,7 +4071,8 @@ const file_master_proto_rawDesc = "" +
 	"\x10has_no_ec_shards\x18\x13 \x01(\bR\rhasNoEcShards\x12U\n" +
 	"\x11max_volume_counts\x18\x04 \x03(\v2).master_pb.Heartbeat.MaxVolumeCountsEntryR\x0fmaxVolumeCounts\x12\x1b\n" +
 	"\tgrpc_port\x18\x14 \x01(\rR\bgrpcPort\x12%\n" +
-	"\x0elocation_uuids\x18\x15 \x03(\tR\rlocationUuids\x1aB\n" +
+	"\x0elocation_uuids\x18\x15 \x03(\tR\rlocationUuids\x12\x0e\n" +
+	"\x02id\x18\x16 \x01(\tR\x02id\x1aB\n" +
 	"\x14MaxVolumeCountsEntry\x12\x10\n" +
 	"\x03key\x18\x01 \x01(\tR\x03key\x12\x14\n" +
 	"\x05value\x18\x02 \x01(\rR\x05value:\x028\x01\"\xcd\x02\n" +