Review and expand testing of UI components in the extension

[FrederikBolding]

Review and expand testing of UI components in the extension including the UI renderer.

The logic grows increasingly complicated in the specific Snaps UI components, mapping functions, interface context and the renderer itself. We should expand our test coverage on the extension side to include unit tests for these systems and components to prevent regressions.

Feel free to break this down into more tickets.

[ajeetd]

Next steps:

• Review and breakdown areas/components into sub issues and then tests can be added for each as separate issues.