fix: viewer anchor adjustments

[haakonflatval-cognite]

Type of change

Jira ticket 📘

https://cognitedata.atlassian.net/browse/

Description 📝

Fix two small issues with ViewerAnchor:

• Make it appear on first render
• Suppress events targeting the viewer anchor

NB: This causes another issue - the "ViewerAnchor" div will still be present in the DOM at its original position, even though the child component may have been translated. They will both suppress events, even if the parent is invisible.

How has this been tested? 🔍

Test instructions ℹ️

Checklist ☑️

• I am proud of this feature.
• I have performed a self-review of my own code.
• I have added PR type (Feat, Bug, Chore, Test, Docs, Style, Refactor) to the PR title.
• I have manually tested this for different scenarios (different models, formats, devices, browsers).
• I have commented my code in hard-to-understand areas.
• I have made corresponding changes to the public documentation.
• I have added unit and visuals tests to prove that my feature works to the best of my ability.
• I have refactored the code for readability to the best of my ability.
• I have checked that my changes do not introduce regressions in the public documentation.
• I have outlined any known defects / lacking capabilities in the contents of this PR.
• I have listed any remaining work that should follow this PR in the description or jira/miro/etc.
• I have added TSDoc to any public facing changes.
• I have added "developer documentation" in any package README.md that is related / applicable to this PR.
• I have noted down and am currently tracking any technical debt introduced in this PR.
• I have thoroughly thought about the architecture of this implementation.
• I have asked peers to test this feature.