feat(A380X/FMS+MFD): Lateral Offset Functionality + FPLN OFFSET Page

[Slightlyclueless]

Fixes #[issue_no]

Summary of Changes

Adds lateral offset functionality to the A380X, Additionally adds the flight planning capability to the shared internal flight planning systems. This means the A32NX could have offset if someone wants to make the layout page for it

Screenshots (if necessary)

TBA

References

Additional context

Discord username (if different from GitHub):
abnormaltoast

Testing instructions

TBA

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

[Slightlyclueless]

I would have ideally seperated out the base offset functionality into a seperate PR, but I had already modified those files by that point.