Move shared code to testlib

Signed-off-by: Andrey Berezin <a.berezin@yadro.com>

src/frostfs_testlib/storage/service_registry.py

@@ -0,0 +1,21 @@
+from frostfs_testlib.storage.dataclasses.node_base import NodeBase, NodeClassDict, ServiceClass
+
+
+class ServiceRegistry:
+    _class_mapping: dict[str, NodeClassDict] = {}
+
+    def get_entry(self, service_type: type[ServiceClass]) -> NodeClassDict:
+        key = service_type.__name__
+
+        if key not in self._class_mapping:
+            raise RuntimeError(
+                f"Unregistered service type requested: {key}. At this moment registered services are: {self._class_mapping.keys()}"
+            )
+
+        return self._class_mapping[key]
+
+    def register_service(self, service_name: str, service_class: type[NodeBase]):
+        self._class_mapping[service_class.__name__] = {
+            "cls": service_class,
+            "hosting_service_name": service_name,
+        }