useful to sort and group packages by their "added on" datetime

qbittorrent has this too...

aka: "created on" datetime of packages

currently the packages table has this schema

CREATE TABLE IF NOT EXISTS "packages" (
    "id" INTEGER PRIMARY KEY AUTOINCREMENT,
    "name" TEXT NOT NULL,
    "folder" TEXT,
    "password" TEXT DEFAULT "",
    "site" TEXT DEFAULT "",
    "queue" INTEGER DEFAULT 0 NOT NULL,
    "packageorder" INTEGER DEFAULT 0 NOT NULL
);

probably the "added on" datetime should be stored as a unix timestamp
(float seconds since 1970 in the UTC timezone)
(float seconds to support batch inserts)
(float seconds or integer milliseconds)