Add ghost virtual webserver for archived htmls

[guerler]

This experimental PR introduces GHOST, a newly written, custom Galaxy visualization that securely loads static websites packaged as ZIP-based QIIME 2 visualization (.qzv) files, or any other package containing an index.html file. The archive is fetched at runtime, unzipped in memory, and served to an embedded iframe via a service worker. This implementation enforces a strict same-origin policy, ensuring that only the necessary resources within the defined scope are served. Any calls to the Galaxy API are blocked to prevent unauthorized access and potential security risks. PR also contains a minor refactoring and style fix for the visualization template.

See: galaxyproject/galaxy-visualizations#93

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.
• Instructions for manual testing are as follows:
  1. [add testing steps and prerequisites here if you didn't write automated tests covering all your changes]

License

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