Add new UI variant for One Dark Theme

[jamievlin]

Add new UI variant for One Dark Theme

Description

Adds a new UI version of one dark theme

Motivation and Context

I am a daily user of the new UI in IntelliJ and the regular one dark theme had different border/spacing than themes for the new UI.

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Non-Functional Change (non-user facing changes)

Checklist:

• My code follows the code style of this project (./gradlew check passes clean).
  • Tip: If you have lint issues just run ./gradlew :ktlintMainSourceSetFormat.
• I updated the changelog with the new functionality.