Updated richViewer for blobs

What does this MR do?

The MR is dependent on the BE part in !25945 (merged).

The MR plugs the new rich viewer for blobs to the already-existing system of processing some special file types (notebook, openapi, pdf, etc.) on the frontend instead of backend.

⚠ Click-testing (if needed) requires the :snippets_vue feature flag to be enabled. In Rails console (rails c):

pry(main)> Feature.enable(:snippets_vue)

Screenshots

Example with a notebook snippet (.ipynb)

Before refactoring	After refactoring, Before this MR	After refactoring, With this MR

Does this MR meet the acceptance criteria?

Conformity

• Changelog entry
• Documentation (if required)
• Code review guidelines
• Merge request performance guidelines
• Style guides
• Database guides
• Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• Tested in all supported browsers
• Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Related to #196797 (closed)