feat: Add A21N Leap ACTs

[vikingnope]

I would like feedback if you notice something incorrect or potentially missing, also if someone could answer the questions I left in the code that would be great. This is only a draft till now.

To search for questions type the following:

• // TODO:
• // ?
• // *
• // !

Summary of Changes

Added ACT 1, 2 and 4 to the A321 Leap

Screenshots (if necessary)

References

Additional context

Discord username (if different from GitHub):

Testing instructions

I would not suggest any testing before I get the correct CSS positioning for the TankReadoutWidget for ACTs 1, 2 & 4.

Should you want to do testing:

1. Refuel the aircraft and make sure that all other tanks are filled up before ACTs start to be filled up. These should get filled in this order: ACT1, ACT2, ACT4
2. Make sure that this fuel has been loaded
3. Try to unload the fuel
4. Try a flight and see that when 11300lb (5000 kg) is reached on the centre tank, it starts to fill up from the ACTs in this order: ACT 4, ACT 2, ACT 1

Mark accordingly if they work:

• Refuel tanks
• Unload tanks
• Tanks transfer

I think that is all, if you think I missed something let me know.

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