Added BalanceTransaction type constants

[nickdnk]

Pretty self-explanatory this one.

Cheers.

[nickdnk]

The only thing that's a bit odd here is that on https://stripe.com/docs/api/balance/balance_transaction#balance_transaction_object-fee_details, the tax_fee is called simply tax.

@ob-stripe Should we include a type tax in this list to be able to use these constants inside fee_details as well?

[ob-stripe]

Thanks Nick!

[ob-stripe]

Released as 6.36.0.

[nickdnk]

Hehe. That was fast. Did you get a chance to read my comment above?

[ob-stripe]

Oops, sorry, I missed it. Technically this is a different attribute so I think it would be more appropriate to define a second set of constants FEE_DETAILS_TYPE_.... However this attribute is not defined as an enum in the OpenAPI spec (despite what the description implies) so I'd rather avoid adding constants for now. It probably should be an enum but I think the current backend implementation makes it difficult. I'll try to clarify with the owning team.

[nickdnk]

@ob-stripe I also think it would be kind of silly to add three constants where two of them already exist on the same object. Much like the overlapping review_reasons on the Review object.