feat(grpc): add DataplaneStatus backend

[sergeymatov]

This is the implementation of rpc GetDataplaneStatus. Real stats collection will be added separately.

[Copilot]

Pull Request Overview

This PR implements the backend infrastructure for the GetDataplaneStatus gRPC endpoint. It introduces comprehensive internal data models for dataplane runtime status (interfaces, BGP, VPCs, FRR, etc.), adds gRPC conversion logic, and wires the request handling through the processor to the gRPC server. The actual collection of real-time statistics is deferred to future work.

Key Changes:

• Added internal status data models with enums, structs, and builder methods
• Implemented bidirectional gRPC conversions for all status types
• Integrated new request/response flow in config processor and gRPC server

Reviewed Changes

Copilot reviewed 7 out of 8 changed files in this pull request and generated 6 comments.

Show a summary per file

File	Description
config/src/internal/status/mod.rs	Defines comprehensive internal models for dataplane status including interfaces, BGP, VPCs, and counters
config/src/converters/grpc/status.rs	Implements TryFrom conversions between internal status models and gRPC protobuf types
mgmt/src/processor/proc.rs	Adds GetDataplaneStatus request/response handling to config processor
mgmt/src/grpc/server.rs	Implements GetDataplaneStatus gRPC endpoint with conversion and error handling
config/src/internal/mod.rs	Exposes new status module
config/src/converters/grpc/mod.rs	Exports status converters and adds round-trip test
Cargo.toml	Updates gateway_config dependency from v0.15.0 to v0.15.1

[mvachhar]

Could you break this into two commits, one that actually adds the server and the other one that adds the conversion code, new types, and tests? It should be too hard since I think that is a file by file split.