feat(wfe-server-protos): add gRPC service definitions for workflow server

13 RPCs in wfe.v1.Wfe service: RegisterWorkflow, StartWorkflow,
GetWorkflow, CancelWorkflow, SuspendWorkflow, ResumeWorkflow,
SearchWorkflows, PublishEvent, WatchLifecycle (stream),
StreamLogs (stream), SearchLogs, ListDefinitions.

wfe-server-protos/src/lib.rs

@@ -0,0 +1,17 @@
+//! Generated gRPC stubs for the WFE workflow server API.
+//!
+//! Built from `proto/wfe/v1/wfe.proto`. Includes both server and client code.
+//!
+//! ```rust,ignore
+//! use wfe_server_protos::wfe::v1::wfe_server::WfeServer;
+//! use wfe_server_protos::wfe::v1::wfe_client::WfeClient;
+//! ```
+
+#![allow(clippy::all)]
+#![allow(warnings)]
+
+include!(concat!(env!("OUT_DIR"), "/mod.rs"));
+
+pub use prost;
+pub use prost_types;
+pub use tonic;