[Dark mode] Redundant white space in the help views

[Andr2ea]

Let's make sure issue is not already fixed in latest builds first.

• [ x ] I verified I can reproduce this issue against latest Integration Build of Eclipse SDK

Steps to reproduce

From a fresh installation and clean workspace:

Window -> Preferences -> General -> Appearance -> Theme: dark

I tried to:
Open any dialog that has a help option (new project, the window -> preferences one, etc)
Click on the help icon

I expected: the "help" tray to open with a uniform background color

But got: black background only in some sections, while the others have a white background

Tested under this environment:

• OS & version: Windows 11
• Eclipse IDE/Platform version: Version: 2023-12 (4.30.0)
  Build id: 20231201-2043

#Additional Info:
The help tray adapts its information based on the context provided in the dialog when the help button is pressed.

Community

• [ x ] I understand reporting an issue to this OSS project does not mandate anyone to fix it. Other contributors may consider the issue, or not, at their own convenience. The most efficient way to get it fixed is that I fix it myself and contribute it back as a good quality patch to the project.