Disable whitelisting before enabling pre / public sales

[basememara]

If a presales or public sales is enabled while whitelisting is enabled, it leaves the dapp in an invalid state. On the left, I enabled public sales when whitelisting was enabled. The sales status shows whitelisting only and public sales price. On the right, it was corrected.

I'm open to discussion because it could be argued that this is a user error and they should know to disable whitelisting before pre/public sales. So this may be more of a convenience and guarding against user error.

Before	After

[liarco]

Hi @basememara, this can be useful but as you said the collection owner would have no clue both sales are open at the same time... I mean, not that users complaining about the issue can be considered a good feedback 😅 but at least it can let them know that people will still be able to mint at the whitelist price if they do that from Etherscan.

Anyway I think this is probably a fix that we should merge and then I can focus on something else to give owners some feedback about what's happening.

Thank you for this, I'm gonna review it asap.

[basememara]

I think throwing an error instead of automatically making a change is better, especially since the whitelist-close script could involve a lot more than contract.whitelistMintEnabled() in the future.

Now running yarn public-sale-open while a whitelisting is open throws an error:

error Please close the whitelist sale before opening a public sale.