Support dark theme in gerkin ewditor

[filippor]

👓 What did you see?

When I use dark theme I see black text on black background

✅ What did you expect to see?

Use color from theme

📦 Which tool/library version are you using?

Cucumber Eclipse 2.0.0.202205250851 cucumber.eclipse.feature.feature.group null

Eclipse
Version: 2022-03 (4.23.0)
Build id: 20220310-1457

🔬 How could we reproduce it?

Set dark theme on Eclipse preferences
open Gerkin File

Steps to reproduce the behavior:

1. Install '...' version '...'
2. Create a file called '....'
3. Run command '....'
4. See error '....'

📚 Any additional context?

---

This text was originally generated from a template, then edited by hand. You can modify the template here.