add tracing and refactor some api pkgs

internal/api/grpc/server/middleware/error_interceptor.go

@@ -0,0 +1,16 @@
+package middleware
+
+import (
+	"context"
+
+	"google.golang.org/grpc"
+
+	grpc_util "github.com/caos/zitadel/internal/api/grpc"
+)
+
+func ErrorHandler() func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+	return func(ctx context.Context, req interface{}, info *grpc.UnaryServerInfo, handler grpc.UnaryHandler) (interface{}, error) {
+		resp, err := handler(ctx, req)
+		return resp, grpc_util.CaosToGRPCError(err)
+	}
+}