Expand Validators.ProjectCanEnableDonations to also require payments to be fully setup

[begedin]

Problem

We should expand the Validators.ProjectCanEnableDonations validator module so it requires the stripe connect account to be fully setup for payments (transfers_enabled needs to be true)

This is part of code-corps/code-corps-ember#947

References

Progress on code-corps/code-corps-ember#947

[joshsmith]

This is actually already implemented.

[joshsmith]

Wrong. We have charges_enabled but not transfers_enabled. It should have both.