Better Union resolution

• cattrs version: 23.1.2
• Python version: 3.10.6
• Operating System: Win 10

Description

Right now I'm looking to migrate from dataclass + dacite to attrs + cattrs, but there's a feature in dacite that I miss in cattrs: consequtive resolution of Unions. What dacite does is that it takes each type in the Union and tries to match it to the data. If nothing is matched - the error is raised. This behavior seemed pretty intuitive for me.
However, if cattrs meets even a really basic Union like Union[str, int, float] and data like '123' it will pretend it doesn't know how to deal with this one, even if the resolution is really straightforward. Yes, you can probably write a hook for that, but manually describing each Union is really undesirable and error-prone. Maybe hook factory solves this, but I'm still figuring this stuff out, and my idea is that this should not be as complicated as it is right now.

What I Did

from attrs import define
from cattrs import structure
from enum import Enum
from typing import Union

c = structure('123', Union[str, int, float])
# Expected behavior: '123'
# Actual behavior: cattrs.errors.StructureHandlerNotFoundError: Unsupported type: typing.Union[str, int, float]. Register a structure hook for it.

@define
class C:
    foo: str

c = structure({'foo': 'bar'}, Union[C, dict])

# Expected behavior: C(foo='bar')
# Actual behavior: cattrs.errors.StructureHandlerNotFoundError: Unsupported type: typing.Union[__main__.C, dict]. Register a structure hook for it.


class Foo(Enum):
    BAR = 'Bar'

c = structure('Bar', Union[Foo, str])

# Expected behavior: Foo.BAR
# Actual behavior: cattrs.errors.StructureHandlerNotFoundError: Unsupported type: typing.Union[__main__.Foo, str]. Register a structure hook for it.

Start with cattrs.structure and reproduce the three Union examples from the issue using the stated Python and cattrs versions. Compare the results with the expected consecutive resolution for str/int/float, attrs class/dict, and Enum/str inputs. Done means these examples resolve as described and unsupported Union inputs still raise an appropriate error.