fix(fms): fix uplink crash for airway terminations not on airways

[BlueberryKing]

Fixes #[issue_no]

Summary of Changes

Due to navigation database disagreements between SimBrief and MSFS, it could happen that SimBrief produces route segments whose terminations still exist in the MSFS navdata, but are no longer on the expected airway. This case is now handled more gracefully.

Screenshots (if necessary)

References

Additional context

Discord username (if different from GitHub):

Testing instructions

• Produce a route on SimBrief with an outdated AIRAC cycle
• Import the route using INIT REQUEST
• There should be scratchpad messages such as AWY/WPT MISMATCH or INTERNAL ERROR, but most of the flightplan should still uplink, albeit with discontinuities between waypoints.

How to download the PR for QA

Every new commit to this PR will cause new A32NX and A380X artifacts to be created, built, and uploaded.

1. Make sure you are signed in to GitHub
2. Click on the Checks tab on the PR
3. On the left side, find and click on the PR Build tab
4. Click on either flybywire-aircraft-a320-neo or flybywire-aircraft-a380-842 download link at the bottom of the page

[alepouna]

QA Report

Discord: alepouna Object of testing: # Tier of Testing: 1 Date: 1/7/2024

Testing Process:

• Use SimBrief oudated AIRACS (2303) and generate routes, import on EFB -> FMGC
• In most routes "INTERNAL ERROR", but route was imported w/ DISCO (as expected)

Testing Results: Passed

Remarks: Longer routes (e.g. ROPOX1J ROPOX UM749 SKP UL617 MAKED DCT LONTA L608 DOLEV DCT OBISA DCT VBA DCT GBG DCT LAMSI L604 MOOCE/N0377F240 L604 ANELA/N0453F360 L604 BIGGE/N0464F380 L604 RELBI L602 RKN L980 TENLI L602 SUPUR P1 GODOS M981 NATEB N97 TLA DCT BRUCE DCT TIR DCT GINGA DCT GOMUP/M078F380 DCT 59N020W 59N030W 59N040W 58N050W DCT DORYY/N0461F380 DCT JOVIE DCT YMO DCT KP15K DCT KP84A DCT KD66U DCT KU51Q DCT PROMT Q88 GARDD DCT LAKRR Q73 HAKMN ANJLL4) take way too long to load so the average user might believe the route is not importing at all.