Allow specifying serializer field configuration using dataclass field metadata?

[oxan]

As @intgr mentioned in #30, it might be nice to support specifying the serializer field configuration using dataclass field metadata.

I've thought about this a bit. It would be helpful and much cleaner if one could pass custom field kwargs overrides using dataclass field(metadata=...), e.g.:

@dataclass
class Example:
    string: str = field(metadata={"drf_field_args": {"allow_blank": True}})
    lst: List[str] = field(metadata={"drf_field_args": {"child": serializers.CharField(allow_blank=True)}})

Does this seem like a mechanism you want to support @oxan?

Or perhaps a metadata key that allows overriding the field as a whole

@dataclass
class Example:
    string: str = field(metadata={"drf_field": serializers.CharField(allow_blank=True)})
    lst: List[str] = field(metadata={
        "drf_field": serializers.ListField(child=serializers.CharField(allow_blank=True))
    })