Remove Duplicated/Unnecessary properties from the HP solution

[hyunbin7303]

Since we are going to keep the user secure data within the Identity service, we don't need to keep those in HP service. Find duplicated properties and remove it.

• FirstName and LastName
• UserId
• Address (Not sure we are keeping it in Identity Service)
• EmailAddress

[hyunbin7303]

    public record Email
    {
        public Email(string emailAddr)
        {
            if (string.IsNullOrWhiteSpace(emailAddr))
                throw new ArgumentNullException(nameof(emailAddr));

            if (!emailAddr.Contains('@'))
                throw new ArgumentException($"Invalid email address: {EmailAddr}", nameof(EmailAddr));

            EmailAddr = emailAddr;
        }

        public string EmailAddr { get; }
        public override string ToString() => this.EmailAddr;
    }