Fixing highlighting of message in message table by id. (6.1)

[dennisoelkers]

Note: This is a backport of #21389 to 6.1.

Description

Motivation and Context

This PR is fixing message highlighting by id in the message table, e.g. when using the "Show surrounding messages" functionality.
Previously, the css function was used inline, which generated invalid css for the left border color.

Fixes #19058.

How Has This Been Tested?

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Refactoring (non-breaking change)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my changes.