Hide outdated visualizations from visualizations activity panel

[guerler]

This PR introduces a visibility flag to the visualization XML, allowing legacy visualizations to be hidden from the visualizations activity panel when users create new visualizations. However, previously saved legacy visualizations will still be accessible via the saved visualizations grid.

The deprecated visualizations include nvd3 and jqplot. Going forward, plotly is the recommended choice. It not only provides enhanced functionality and better support compared to the legacy visualization types but also utilizes a modern vite/vue3-based build system that is far more reliable. Previously, visualizations needed to be rebuilt within the context of the Galaxy client, which often resulted in build failures. With the new system, visualizations are built independently of Galaxy client internals and build bundles, and then published to npm, ensuring a more streamlined and robust process.

How to test the changes?

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• I've included appropriate automated tests.
• This is a refactoring of components with existing test coverage.
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License

• I agree to license these and all my past contributions to the core galaxy codebase under the MIT license.