fix: deepcopy component output to avoid overriding previous outputs (#3698)

* Fixes copy of component outputs

* Fix issue with copying outputs in custom components

- Update loop to iterate over `_outputs.values()` instead of `outputs` to ensure correct attribute setting.

* Refactor output handling in custom component to use dictionary values

- Updated methods to iterate over `_outputs.values()` instead of `outputs`.
- Ensured consistent access to output values across various methods.
- Fixed potential issues with output value resetting and state model building.

* Fix incorrect attribute reference in set_output_value method

* Add missing import for CustomComponent in test_custom_component.py

* Refactor `test_read_flow` to generate unique flow names for each test run

* Refactor: Rename `_outputs` to `_outputs_map` in custom component

- Updated all references of `_outputs` to `_outputs_map` in `component.py` to improve clarity and consistency.
- Adjusted related methods and attributes in `base.py` to align with the new naming convention.

* Fix output handling in custom component

- Moved `_reset_all_output_values` call to ensure outputs are reset after initialization.
- Updated attribute access to use `_outputs_map` instead of `_outputs` for consistency.

---------

Co-authored-by: Gabriel Luiz Freitas Almeida <gabriel@langflow.org>

src/backend/tests/unit/test_custom_component.py

@@ -400,6 +400,7 @@ def test_custom_component_get_function_entrypoint_args_no_args():
     the CustomComponent class with a build method with no arguments.
     """
     my_code = """
+from langflow.custom import CustomComponent
 class MyMainClass(CustomComponent):
     def build():
         pass"""

src/backend/tests/unit/test_database.py

@@ -73,10 +73,11 @@ def test_read_flows(client: TestClient, json_flow: str, active_user, logged_in_h
     assert len(response.json()) > 0
 
 
-def test_read_flow(client: TestClient, json_flow: str, active_user, logged_in_headers):
+def test_read_flow(client: TestClient, json_flow: str, logged_in_headers):
     flow = orjson.loads(json_flow)
     data = flow["data"]
-    flow = FlowCreate(name="Test Flow", description="description", data=data)
+    unique_name = str(uuid4())
+    flow = FlowCreate(name=unique_name, description="description", data=data)
     response = client.post("api/v1/flows/", json=flow.model_dump(), headers=logged_in_headers)
     flow_id = response.json()["id"]  # flow_id should be a UUID but is a string
     # turn it into a UUID