Add SteelJet virtual airline

[rpuig2001]

🔗 Your VATSIM ID

1410399

🔗 Linked Issue

None

❓ Type of change

• ✈️ Airline Changes
• [x ] 🆕 New Airline
• 🧹 Technical change (refactoring, updates and other improvements)

📚 VA Website

Only internal: https://steeljet.up.railway.app/

📚 Description

Adds SteelJet virtual airline divisions SJC, SJL, SJE to the list of callsigns.

[rpuig2001]

Failing due to SJC already existing.
Kindly inform if exists any workaround to display in Vatsim Radar the corresponding callsign. Otherwise this PR can be closed.

Thanks for your support as always!

[daniluk4000]

Error: SJC virtual airline already exists

[daniluk4000]

And yes, you can already use remarks method to show your airline without this dataset :)

[rpuig2001]

Thank you!
I tried:
CS/STEEL CARGO and CS/STEEL CARGO/STEELJET.
Any of them worked. Any hint @daniluk4000?

Ref: https://docs.vatsim-radar.com/contributing/va