Fix default_value error on enum type

[haodt]

Hello, this PR aiming to fix the issue #1081 for the time being before we could come up with anything better.

Currently i'm trying to understand how notation and schema work so i tried my best at fixing the validation which is desirable for the time being since we are having troubles trying to upgrade our absinthe from 1.5.5 to 1.6.6. This issue caused everything to explode ( we indeed used alot of default value).

Any guidances would be appreciated!

[haodt]

hey @benwilson512 any thoughts on this one?

[katafrakt]

I just wanted to bump this as I stumbled upon the bug it solves today. The fix looks correct to me. I'd be happy to help if there's something more required to get this merged.

[Helge801]

Would love to see this merged in. 🙏

[sraka1]

Bumping this as well. Tagging @benwilson512 again, this seems like a quick merge

[anvox]

Hey @benwilson512 Do you think we could go with this approach or suggest anything else? This issue blocked us from upgrading absinthe for a long time.

[anvox]

We came to another workaround that removing default value from enum params. Default value is checked and filled by resolver. It's a bit more code but unblock upgrading.

[HarshBalyan]

@benwilson512 please, review this PR!