Split accounts and personal information

[MarcTroll]

Currently personal information and account names are saved in one database table. Split this table into two tables like

user_account(
    userID: foreignkey to user
    accountID: primary key, auto increment
    displayName: The name the user account will be displayed with
)

user_account_personal_information(
    accountID: foreignkey to user_account.accountID
    gender
    forename
    surname
    address
    phonenumber
)

Doing this allows storing placeholder accounts in the table user_accounts, that don't need personal information (due to the reason that placeholders are just names, that can be used to define a reservation, that is not applicable to an explicit user (e.g. training, tournaments, ...).