fix: Empty GridLogViewer when messages are appended before the element is on screen

[Eideren]

PR Details

See title, the issue is specifically related to this window, if it hasn't been opened before and an error message is sent to it, opening it would show an empty list even though the tab mentions a non-zero amount of asset errors

This PR makes sure to fill in the message list as soon as the element is created.

Related Issue

None afaict

Types of changes

• Docs change / refactoring / dependency upgrade
• 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)

Checklist

• My change requires a change to the documentation.
• I have added tests to cover my changes.
• All new and existing tests passed.
• I have built and run the editor to try this change out.