feat(zk_toolbox): Add prover init command (matter-labs#2298)

## What ❔

Add prover init command.

Initializes proof object storage settings.

## Checklist

<!-- Check your PR fulfills the following items. -->
<!-- For draft PRs check the boxes as you complete them. -->

- [x] PR title corresponds to the body of PR (we generate changelog
entries from PRs).
- [x] Tests for the changes have been added / updated.
- [x] Documentation comments have been added / updated.
- [x] Code has been formatted via `zk fmt` and `zk lint`.

core/lib/protobuf_config/src/lib.rs

@@ -35,9 +35,10 @@ mod utils;
 mod vm_runner;
 mod wallets;
 
-use std::str::FromStr;
+use std::{path::PathBuf, str::FromStr};
 
-use zksync_protobuf::ProtoRepr;
+use anyhow::Context;
+use zksync_protobuf::{serde::serialize_proto, ProtoRepr};
 use zksync_types::{H160, H256};
 
 fn parse_h256(bytes: &str) -> anyhow::Result<H256> {
@@ -51,3 +52,20 @@ fn parse_h160(bytes: &str) -> anyhow::Result<H160> {
 pub fn read_optional_repr<P: ProtoRepr>(field: &Option<P>) -> anyhow::Result<Option<P::Type>> {
     field.as_ref().map(|x| x.read()).transpose()
 }
+
+pub fn decode_yaml_repr<T: ProtoRepr>(
+    path: &PathBuf,
+    deny_unknown_fields: bool,
+) -> anyhow::Result<T::Type> {
+    let yaml = std::fs::read_to_string(path).with_context(|| path.display().to_string())?;
+    let d = serde_yaml::Deserializer::from_str(&yaml);
+    let this: T = zksync_protobuf::serde::deserialize_proto_with_options(d, deny_unknown_fields)?;
+    this.read()
+}
+
+pub fn encode_yaml_repr<T: ProtoRepr>(value: &T::Type) -> anyhow::Result<Vec<u8>> {
+    let mut buffer = vec![];
+    let mut s = serde_yaml::Serializer::new(&mut buffer);
+    serialize_proto(&T::build(value), &mut s)?;
+    Ok(buffer)
+}

core/lib/protobuf_config/src/tests.rs

@@ -1,12 +1,8 @@
 use std::{path::PathBuf, str::FromStr};
 
-use anyhow::Context;
-use zksync_protobuf::{
-    testonly::{test_encode_all_formats, ReprConv},
-    ProtoRepr,
-};
+use zksync_protobuf::testonly::{test_encode_all_formats, ReprConv};
 
-use crate::proto;
+use crate::{decode_yaml_repr, proto};
 
 /// Tests config <-> proto (boilerplate) conversions.
 #[test]
@@ -45,16 +41,6 @@ fn test_encoding() {
     test_encode_all_formats::<ReprConv<proto::observability::Observability>>(rng);
 }
 
-pub fn decode_yaml_repr<T: ProtoRepr>(
-    path: &PathBuf,
-    deny_unknown_fields: bool,
-) -> anyhow::Result<T::Type> {
-    let yaml = std::fs::read_to_string(path).with_context(|| path.display().to_string())?;
-    let d = serde_yaml::Deserializer::from_str(&yaml);
-    let this: T = zksync_protobuf::serde::deserialize_proto_with_options(d, deny_unknown_fields)?;
-    this.read()
-}
-
 #[test]
 fn verify_file_parsing() {
     let base_path = PathBuf::from_str("../../../etc/env/file_based/").unwrap();