[WIP] Introduced new Flight File Processing System

[jkarns275]

This new system aims to do a few things:

• Completely separated flight importing / processing code from Flight.java
• Create a readable and clear interface for processing steps.
• Remove boilerplate code.
• Parallelize flight file processing.
• Automatically resolve dependencies between flight importing steps.

The basic idea is that we have a set of "steps" that we want to apply to flights during the import process (e.g. AGL calculation, LOCI calculation, AirportProximity, Engine Divergence, TotalFuel). Each of these steps will be factored into its own class that extends the ProcessStep class, which will provide some information about what columns the steps need to be computed and what columns they output after being computed.

This information can be used to construct a DAG, where the nodes are the process steps and an edge exists between from node A to node B if node A outputs a column required by column B. The DAG can then be executed efficiently using a work-stealing thread pool (ForkJoinPool in java) along with a little extra book keeping to avoid creation of redundant jobs. The implementation of this DAG exists in org.ngafid.flights.process.DependencyGraph.

The FlightBuilder class pulls these things together. The (overridable) method gatherSteps() returns a list of ProcessSteps which will be used create a DependencyGraph. The graph is then executed. Rather than modifying the Flight object in-place, the FlightBuilder object as passed around to the ProcessSteps.

To handle different types of Airframes that may require a particular set of ProcessSteps, the FlightBuilder class can be extended and the gatherSteps() method overridden.

Error handling here is a bit more convoluted since (1) the DAG can possibly be executed in parallel and (2) the errors can propagate down the dependency graph. Basically, non-fatal exceptions are accumulated as usual but will lead to all descendant steps being disabled. Fatal exceptions will lead to the flight ultimately not being imported, but won't immediately halt the processing process due to the usage of a thread pool.

There are also a lot of small changes I made along the way here for the sake of speed / efficiency / readability, too many to list here.

TODO:

• Scan Eagle Process steps.
• Create FlightBuilder classes for different classes of airframe (rotorcraft, UAV)

Also note that this is a PR into our staging branch, not main.