Bugfix: added from errors factory methods

[zbyszekprasak]

In README.md there are examples of creating ErrorOr form single error as well as list of errors using ErrorOrFactory.From<int>(errors) but in library no such method exist. Here are implementations of those methods. Additionally ErrorOr<TValue>.From(errors) method is being marked as obsolete.

Examples:

ErrorOr<int> result = ErrorOrFactory.From<int>(Error.Unexpected());
ErrorOr<int> result = ErrorOrFactory.From<int>([Error.Validation(), Error.Validation()]);

public ErrorOr<int> MultipleErrorsToErrorOr()
{
    return ErrorOrFactory.From([
        Error.Validation(description: "Invalid Name"),
        Error.Validation(description: "Invalid Last Name")
    ]);
}

// Now obsolete
ErrorOr<Person> errorOrPerson = ErrorOr<Person>.From([Error.Validation(), Error.Validation()]);