use field aliases when serializing pydantic objects (dagster-io#21325)

## Summary & Motivation

["An alias is an alternative name for a field, used when serializing and
deserializing data."](https://docs.pydantic.dev/latest/concepts/alias/)

The motivation for this is moving `MetadataValue` subclasses to
`DagsterModel`s, e.g. here:
dagster-io#21324.

## How I Tested These Changes

python_modules/dagster/dagster/_serdes/serdes.py

@@ -672,11 +672,26 @@ def constructor_param_names(self) -> Sequence[str]:
 
 class PydanticModelSerializer(ObjectSerializer[T_PydanticModel]):
     def object_as_mapping(self, value: T_PydanticModel) -> Mapping[str, Any]:
-        return value.__dict__
+        value_dict = value.__dict__
+
+        result = {}
+        for key, field in self.klass.__fields__.items():
+            if field.alias is None and (
+                getattr(field, "serialization_alias", None) is not None
+                or getattr(field, "validation_alias", None) is not None
+            ):
+                raise SerializationError(
+                    "Can't serialize pydantic models with serialization or validation aliases. Use "
+                    "the storage_field_names argument to whitelist_for_serdes instead."
+                )
+            result_key = field.alias if field.alias else key
+            result[result_key] = value_dict[key]
+
+        return result
 
     @property
     def constructor_param_names(self) -> Sequence[str]:
-        return list(self.klass.__fields__.keys())
+        return [field.alias or key for key, field in self.klass.__fields__.items()]
 
 
 class FieldSerializer(Serializer):

python_modules/dagster/dagster_tests/general_tests/test_serdes.py

@@ -25,6 +25,7 @@
     unpack_value,
 )
 from dagster._serdes.utils import hash_str
+from pydantic import Field
 
 
 def test_deserialize_value_ok():
@@ -890,3 +891,84 @@ class MyEnt(pydantic.BaseModel):
     # can deserialize previous NamedTuples in to future pydantic models
     py_dc_ent = deserialize_value(ser_nt_ent, whitelist_map=py_m_env)
     assert py_dc_ent
+
+
+def test_pydantic_alias():
+    test_env = WhitelistMap.create()
+
+    @_whitelist_for_serdes(test_env)
+    class SomeDagsterModel(DagsterModel):
+        unaliased_id: int = Field(..., alias="id_alias")
+        name: str
+
+    o = SomeDagsterModel(id_alias=5, name="fdsk")
+    packed_o = pack_value(o, whitelist_map=test_env)
+    assert packed_o == {"__class__": "SomeDagsterModel", "id_alias": 5, "name": "fdsk"}
+    assert unpack_value(packed_o, whitelist_map=test_env, as_type=SomeDagsterModel) == o
+
+    ser_o = serialize_value(o, whitelist_map=test_env)
+    assert deserialize_value(ser_o, whitelist_map=test_env) == o
+
+
+def test_pydantic_serialization_alias():
+    test_env = WhitelistMap.create()
+
+    @_whitelist_for_serdes(test_env)
+    class SomeDagsterModel(DagsterModel):
+        unaliased_id: int = Field(..., serialization_alias="id_alias")
+        name: str
+
+    o = SomeDagsterModel(unaliased_id=5, name="fdsk")
+    with pytest.raises(
+        SerializationError,
+        match="Can't serialize pydantic models with serialization or validation aliases.",
+    ):
+        serialize_value(o, whitelist_map=test_env)
+
+    with pytest.raises(
+        SerializationError,
+        match="Can't serialize pydantic models with serialization or validation aliases.",
+    ):
+        pack_value(o, whitelist_map=test_env)
+
+
+def test_pydantic_validation_alias():
+    test_env = WhitelistMap.create()
+
+    @_whitelist_for_serdes(test_env)
+    class SomeDagsterModel(DagsterModel):
+        unaliased_id: int = Field(..., validation_alias="id_alias")
+        name: str
+
+    o = SomeDagsterModel(id_alias=5, name="fdsk")
+    with pytest.raises(
+        SerializationError,
+        match="Can't serialize pydantic models with serialization or validation aliases.",
+    ):
+        serialize_value(o, whitelist_map=test_env)
+
+    with pytest.raises(
+        SerializationError,
+        match="Can't serialize pydantic models with serialization or validation aliases.",
+    ):
+        pack_value(o, whitelist_map=test_env)
+
+
+def test_pydantic_alias_generator():
+    test_env = WhitelistMap.create()
+
+    @_whitelist_for_serdes(test_env)
+    class SomeDagsterModel(DagsterModel):
+        id: int = Field(...)
+        name: str
+
+        class Config:
+            alias_generator = lambda field_name: f"{field_name}_alias"
+
+    o = SomeDagsterModel(id_alias=5, name_alias="fdsk")
+    packed_o = pack_value(o, whitelist_map=test_env)
+    assert packed_o == {"__class__": "SomeDagsterModel", "id_alias": 5, "name_alias": "fdsk"}
+    assert unpack_value(packed_o, whitelist_map=test_env, as_type=SomeDagsterModel) == o
+
+    ser_o = serialize_value(o, whitelist_map=test_env)
+    assert deserialize_value(ser_o, whitelist_map=test_env) == o