feat(a380x/pfd): Add FCU ALT ABOVE/BELOW A/C FMA messages

[Pruznak]

Fixes #9410

Summary of Changes

Adds the "FCU ALT ABOVE A/C" and "FCU ALT BELOW A/C" FMA messages

Screenshots (if necessary)

References

Issue linked

Additional context

Discord username (if different from GitHub): Pruznak

Testing instructions

1. Load up aircraft, take off, climb to any altitude
2. Select the HDG / VS mode on the FCU
3. Select any positive VS, any altitude below current one and engage VS - make sure "FCU ALT BELOW A/C" is displayed on the FMA and does not disappear until you either: 1) Set VS to 0 or 2) Set VS to any negative value or 3) Disengage VS (switch to any other vertical mode)
4. Select any negative VS, any altitude above current one and engage VS - make sure "FCU ALT ABOVE A/C" is displayed on the FMA and disappears only after: 1) roughly 10 seconds have passed since it displayed or 2) You set VS to 0 or 3) You set VS to any positive value or 4) You disengage VS (switch to any other vertical mode)
5. Switch to TRK / FPA mode on the FCU and repeat steps 3 and 4 with FPA
6. Make sure when switching HDG / VS and TRK / FPA modes while either message is displayed doesn't result in it disappearing

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, flybywire-aircraft-a380-842 (4K) or flybywire-aircraft-a380-842 (8K) download link at the bottom of the page

[flogross89]

Had a quick look over some parts, but in general that's exactly how you can and should use MappedSubjects :)

[flogross89]

Looks good to me now, thank you! And sorry for the late re-review, slipped through. Feel free to ping me on Discord or here if a reply takes more than one week.

[Pruznak]

Looks good to me now, thank you! And sorry for the late re-review, slipped through. Feel free to ping me on Discord or here if a reply takes more than one week.

Thanks for the review! No problem, I just figured you had a lot of work and didn't want to "annoy" you :D Okay, I'll do next time, thanks!

[BravoMike99]

Please resolve conflicts when able

[Pruznak]

Please resolve conflicts when able

I'm trying to, it's just that I'm having some issues, that's why there are so many commits right now, sorry for that.

[BravoMike99]

Please resolve conflicts when able

I'm trying to, it's just that I'm having some issues, that's why there are so many commits right now, sorry for that.

No worries, I guess it must have been the disconnect ap for landing pr which got merged since then. Don't hesitate to ask for help on the discord if you need (ignore the close, miss click on mobile 😅 )

[Pruznak]

Please resolve conflicts when able

I'm trying to, it's just that I'm having some issues, that's why there are so many commits right now, sorry for that.

No worries, I guess it must have been the disconnect ap for landing pr which got merged since then. Don't hesitate to ask for help on the discord if you need (ignore the close, miss click on mobile 😅 )

You're right, the issues were because of that code 😅 Thanks, I managed to fix it (I hope it'll work out on the first try next time), so conflicts resolved 👍