feat(isEmail): added allowed_wildcard option for isEmail validator

[toofff]

The isEmail validator uses the isFQDN validator, which has the option allowed_wildcard.

For a project I need to validate an email with a wildcard. I simply add the allowed_wildcard option to the isEmail validator so that it can pass the option to the isFQDN validator.

Checklist

• [x] PR contains only changes related; no stray files, etc.
• [x] README updated (where applicable)
• [x] Tests written (where applicable)
• [ ] References provided in PR (where applicable)

[rubiin]

I think this would break the meaning of isEmail validator. For wildcard validation, pattern matching would be more feasible than using it on isEmail.

[toofff]

@rubiin Do you have an example of how to use filtering?

To give you a bit more context, for my business case I'd like to validate an email field that can also have emails with wildcards, which is why I came up with this proposal.

For the moment, what I've found on my side is to do a 2-step validation. I use the isFQDN method to validate the domain of my email, then I remove the wildcard to validate my email with the isEmail method. But I don't find this very fun to do.

If you have a simpler idea, I'd love to hear it.

[WikiRik]

I agree with @rubiin, isEmail should only validate valid emails. Your 2-step validation seems like a reasonable workaround to me.