feat: enhance gRPC client with state management and reconnection logic

- Introduced state management in GrpcClient to monitor and handle connection states effectively.
- Added a reconnect channel and a state monitoring goroutine to facilitate automatic reconnections on state changes.
- Updated the connect method to initiate a reconnection loop upon connection loss.
- Enhanced logging for connection state changes and errors during connection attempts.
- Refactored tests to ensure proper initialization of gRPC client and server, improving test reliability and coverage.

core/task/handler/runner.go

@@ -75,14 +75,14 @@ type Runner struct {
 
 // Init initializes the task runner by updating the task status and establishing gRPC connections
 func (r *Runner) Init() (err error) {
+	// wait for grpc client ready
+	client2.GetGrpcClient().WaitForReady()
+
 	// update task
 	if err := r.updateTask("", nil); err != nil {
 		return err
 	}
 
-	// wait for grpc client ready
-	client2.GetGrpcClient().WaitForReady()
-
 	// grpc task service stream client
 	if err := r.initConnection(); err != nil {
 		return err