fix(fms): pd format accepts sign

[tracernz]

Fixes #[issue_no]

Summary of Changes

The P/D format now accepts an optional leading sign on the distance.

Note: as the feature is not yet implemented, I decided a changelog entry will only cause confusion.

Screenshots (if necessary)

References

Pylots; not books.

Additional context

Discord username (if different from GitHub):

Testing instructions

Setup a flight plan, type place/dist format (<any waypoint/fix/navaid in your plan>/<optional + or - sign, then a distance up to 999.9> e.g. OCK/-5) on the scratchpad and try to insert it into the flightplan; you should get "NOT YET IMPLEMENTED" on the scratchpad.

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, click on the bottom PR tab
4. Click on either flybywire-aircraft-a320-neo or flybywire-aircraft-a380-842 download link at the bottom of the page

[noonebling]

Quality Assurance Trainee Report

Discord : noonebling
Object of testing: 8582
Tier of Testing : 1
Date : 28/03/2024

Testing Process:

1. Start up Sim
2. Setup a flightplan
3. type place/dist format (<any waypoint/fix/navaid in your plan>/<optional + or - sign, then a distance up to 999.9> e.g. OCK/-5) on the scratchpad and try to insert it into the flightplan; you should get "NOT YET IMPLEMENTED" on the scratchpad.

Negatives:
N/A

Testing Results:
Passed

Conclusions:
Works as expected