fix(a380x/eng): Display simple oil quantity estimation

[flogross89]

Fixes #9258

Summary of Changes

We already have a very simple estimation of oil quantity, this displays it on the SD ENG page.
To be replaced by better simulation once we have a new engine model.
Used old code, ported it.

Screenshots (if necessary)

References

References for RR Trent 900 max. oil quantity surprisingly hard to find.

https://youtu.be/p28erS6uWHE?si=80yzzw8NgSvWhmzw&t=1869

Additional context

Discord username (if different from GitHub): floridude

Testing instructions

Perform cold&dark startup, take-off, fly around a bit, engine should perform without problems (oil qty and oil temp should not be zero, oil temp doesn't make sense still)

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]

Quality Assurance Report

Discord Username : floridude
Object of testing : #9785
Aircraft : A380X
Tier of Testing : 1
Date : 20/01/2025

Testing Process:
Load cold&dark, start engines, take-off, fly for ca. one hour and verify engine parameters are as expected.

Oil quantity: Initialized with random deviations, also readable before engine start when powering FADECs, oil gulp seems plausible. During climb, quantity remains >13 qt

Oil temperature: Initialized with ambient temperature, rises to 85 deg after engine start and remains there until climb, decreased to around 75 °C during cruise. Not too plausible (too high), but I'll take it.

Oil pressure: Remained below 100 PSI, no references known but seems plausible given the overall state of the engine model.

Shortly after take-off:

Climb, FL270:

Cruise FL400:

Open descend (idle thrust):

Testing Results:
Passed