Time selector should fetch its options from BE

[ivalime]

There should be a single place where these values are defined/changed instead of being defined on both FE and BE

	switch frequency {
	case "5-minutely":
		return "*/5 * * * *"
	case "hourly":
		return fmt.Sprintf("%d * * * *", startTime.Minute())
	case "daily":
		return fmt.Sprintf("%d %d * * *", startTime.Minute(), startTime.Hour())
	case "weekly":
		return fmt.Sprintf("%d %d * * %d", startTime.Minute(), startTime.Hour(), startTime.Weekday())
	case "monthly":
		return fmt.Sprintf("%d %d %d * *", startTime.Minute(), startTime.Hour(), startTime.Day())
	default:
		return ""
	}

export type Frequency = "minute" | "hour" | "day" | "week" | "month";