This table used to store majority fee of monero nettype.
By calculating majority fee via "cron" every 300s, the function to
get majority fee for nettypes can be done with single query.
The frontend majority static data in the frontend removed and
now use `/api/v1/fees` endpoint to get majority fee value.
Note: Don't know if it works well with `onload` method or not. Let see.
Adding struct chan to run cron Process to stop the goroutine.
Moving db migration inside `fiber.IsChild` block
to avoid multiple execution migration script when in prefork mode.
Give additional time for graceful shutdown.
