Add storage_broker binary.

Which ought to replace etcd. This patch only adds the binary and adjusts
Dockerfile to include it; subsequent ones will add deploy of helm chart and the
actual replacement.

It is a simple and fast pub-sub message bus. In this patch only safekeeper
message is supported, but others can be easily added.

Compilation now requires protoc to be installed. Installing protobuf-compiler
package is fine for Debian/Ubuntu.

ref
https://github.com/neondatabase/neon/pull/2733
https://github.com/neondatabase/neon/issues/2394

libs/utils/src/id.rs

@@ -3,6 +3,13 @@ use std::{fmt, str::FromStr};
 use hex::FromHex;
 use rand::Rng;
 use serde::{Deserialize, Serialize};
+use thiserror::Error;
+
+#[derive(Error, Debug)]
+pub enum IdError {
+    #[error("invalid id length {0}")]
+    SliceParseError(usize),
+}
 
 /// Neon ID is a 128-bit random ID.
 /// Used to represent various identifiers. Provides handy utility methods and impls.
@@ -22,6 +29,15 @@ impl Id {
         Id::from(arr)
     }
 
+    pub fn from_slice(src: &[u8]) -> Result<Id, IdError> {
+        if src.len() != 16 {
+            return Err(IdError::SliceParseError(src.len()));
+        }
+        let mut id_array = [0u8; 16];
+        id_array.copy_from_slice(src);
+        Ok(id_array.into())
+    }
+
     pub fn as_arr(&self) -> [u8; 16] {
         self.0
     }
@@ -100,6 +116,10 @@ macro_rules! id_newtype {
                 $t(Id::get_from_buf(buf))
             }
 
+            pub fn from_slice(src: &[u8]) -> Result<$t, IdError> {
+                Ok($t(Id::from_slice(src)?))
+            }
+
             pub fn as_arr(&self) -> [u8; 16] {
                 self.0.as_arr()
             }