feat(afs): Add FMGC and FCU computer implementation

[lukecologne]

Fixes #4242, Fixes #6717, Fixes #6089, Fixes #2606, Fixes #8319, Fixes #8000, Fixes #8294, Fixes #8397
Supersedes #7301

Summary of Changes

This PR aims to add:

• Fully simulated dual FMGCs (only flight guidance part)
• Fully simulated FCU

including the correct communication of these two computers with the peripheral devices and the rest of the systems and displays.

To Do until feature parity:

• Improve FCU target speed handling:
  • Speed preselection
  • SPD/MACH switching
• FD engagement at GA
• reversion to HDG/VS reference at GA
• Provision for FINAL APP
• Fix SRS RWY A/THR timing
• Verify and possibly update mode conditions with FCOM to account for changes due to FG software updates:
  • NAV at GA
  • FD disengagement at global speed protection
  • Keep lateral approach mode at voluntary vertical approach mode disengagement (seems to be optional?)
  • LOC backcourse support
  • Polar Nav
  • TCAS mode
  • Engage V/S mode after being in the air for 5s without any other vertical mode engaged
• Add FMGC to FDR
• Left/Right EFIS panel sync
• Fix intermittent issues with hard pitch orders during ALT*, reducing the V/S too much, and sometimes unexplained pitch down during flare in autolands (possibly only happening with simulink in the loop, to be tested)
• Improve A/THR response, especially during approach
• Fix Baro autoset event
• Add THR LK indication on FMA
• Auto-engage selected speed control at FMGC powerup in the air
• Fix ATHR Soft conditions

Bonus ToDos:

• Add proper startup sequence and timing for FMGCs and FCU
• Improve documentation on Simulink model

Screenshots (if necessary)

References

Additional context

Discord username (if different from GitHub):

Testing instructions

As this PR completely reimplements the FG and FCU logic, extensive testing is needed. The laws are unchanged, but still could be affected by the integration in the FMGC.
Possible tests (non-exhaustive, you can be creative here :) ):

• Various full flights with different approach types, departures (thrust setting, departure runway ILS...) etc.
• Uncommon "non-abnormal" procedures, for example: takeoffs without V2, heading preset, TCAS ...
• Various Abnormals
  Also, tests with various setups (such as hardware FCUs) would be nice to have

How to download the PR for QA

Every new commit to this PR will cause a new A32NX artifact 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, click on the bottom PR tab
4. Click on the A32NX download link at the bottom of the page