Headercolor is random

[DenisZagitov]

Hello! Thank you for this plugin! Could you please set the table's color according to table settings (https://dbml.dbdiagram.io/docs/#table-settings)?

Table users [headercolor: #3498DB] {
    id integer [primary key]
    username varchar(255) [not null, unique]
}

It's also would be nice to save position of existing tables on canvas)