Add single node Raft metadata store with memory storage

This commit adds the skeleton of the Raft metadata store. At the moment
only a single node with memory storage is supported.

This fixes restatedev#1785.

crates/metadata-store/Cargo.toml

@@ -18,6 +18,7 @@ restate-rocksdb = { workspace = true }
 restate-types = { workspace = true }
 
 anyhow = { workspace = true }
+assert2 = { workspace = true }
 async-trait = { workspace = true }
 bytes = { workspace = true }
 bytestring = { workspace = true }
@@ -29,9 +30,12 @@ hyper = { workspace = true }
 hyper-util = { workspace = true }
 prost = { workspace = true }
 prost-types = { workspace = true }
+protobuf = "2.28.0"
+raft = { version = "0.7.0" }
 rocksdb = { workspace = true }
 schemars = { workspace = true, optional = true }
 serde = { workspace = true }
+slog = { version = "2.7.0" }
 static_assertions = { workspace = true }
 thiserror = { workspace = true }
 tokio = { workspace = true }
@@ -43,6 +47,8 @@ tonic-health = { workspace = true }
 tower = { workspace = true }
 tower-http = { workspace = true, features = ["trace"] }
 tracing = { workspace = true }
+tracing-slog = { version = "0.3.0" }
+ulid = { workspace = true, features = ["serde"] }
 
 [dev-dependencies]
 restate-core = { workspace = true, features = ["test-util"] }

crates/metadata-store/src/grpc/handler.rs

@@ -132,7 +132,7 @@ impl MetadataStoreSvc for MetadataStoreHandler {
 impl From<RequestError> for Status {
     fn from(err: RequestError) -> Self {
         match err {
-            RequestError::FailedPrecondition(msg) => Status::failed_precondition(msg),
+            RequestError::FailedPrecondition(msg) => Status::failed_precondition(msg.to_string()),
             err => Status::internal(err.to_string()),
         }
     }