ACARS table should save the route

[nabeelio]

While the actual flight path is being saved, the underlying route is calculated dynamically from the route column, based on the navdata that's loaded into the database.

• Add a column for type, to hold an enum of AcarsType
• Add enum AcarsType
• When ACARS updates are sent, save with type of ACARS::FLIGHT_PATH
• When the final file step is called, generated the ACARS route data as AcarsType::ROUTE

AcarsType

• FLIGHT_PATH - this is the actual route being flown
• ROUTE - this is the filed route

class AcarsType {
    FLIGHT_PATH = 0;
    ROUTE = 1;
}