fix: add FXLegData to ProcedureLeg union

[MikeRomaa]

I'm currently writing an interface using your JS package and noticed that the type of ProcedureLeg does not include FXLegData.

At first I assumed that this was intentional, but I later faced issues when processing the DEGE3S.RW16 departure from LSZH, which includes an FA leg despite transitions having a legs type of ProcedureLeg[]. I've also noticed this with the GERS1H.RW34 departure, which contains an FD leg.

I also noticed that FC legs were missing from the FXLegData union, which came up on the L34RY.KAIHO approach into RJTT, and so were PI legs which came up on the L20.HRV approach into KMSY.

[MikeRomaa]

Also noticed that FC legs came up as procedure legs, and were completely missing from the type. I used the following queries to determine the types for FCLegData fields:

• All distances are given in nautical miles:

  SELECT DISTINCT(route_distance_holding_distance_time)
  FROM tbl_pf_iaps
  WHERE path_termination = 'FC'

• turn_direction is optional:

  SELECT DISTINCT(turn_direction)
  FROM tbl_pf_iaps
  WHERE path_termination = 'FC'

• Altitude constraints may be of types other than +:

  SELECT DISTINCT(altitude_description)
  FROM tbl_pf_iaps
  WHERE path_termination = 'FC'

• recommended_navaid, course, rho, and theta are mandatory:

  SELECT COUNT(*)
  FROM tbl_pf_iaps
  WHERE
      path_termination = 'FC' AND
      (
          recommended_navaid IS NULL OR
          course IS NULL OR
          rho IS NULL OR
          theta IS NULL
      )

Of course it's entirely possible that I've missed fields, so please let me know if this looks right.

[professoralex13]

Whoops I forgot those 😆
lgtm