add nextblock, 0slot support

jito_protos/src/grpc/shared.rs

@@ -0,0 +1,18 @@
+// This file is @generated by prost-build.
+#[derive(Clone, Copy, PartialEq, ::prost::Message)]
+pub struct Header {
+    #[prost(message, optional, tag = "1")]
+    pub ts: ::core::option::Option<::prost_types::Timestamp>,
+}
+#[derive(Clone, Copy, PartialEq, ::prost::Message)]
+pub struct Heartbeat {
+    #[prost(uint64, tag = "1")]
+    pub count: u64,
+}
+#[derive(Clone, PartialEq, ::prost::Message)]
+pub struct Socket {
+    #[prost(string, tag = "1")]
+    pub ip: ::prost::alloc::string::String,
+    #[prost(int64, tag = "2")]
+    pub port: i64,
+}