Render blob viewer Vue app

What does this MR do?

Currenly when viewing a blob/file (repository -> file), we use haml-based blob viewers to view the blob/file. This MR is part of a bigger effort to Extend the repository Vue app to also show Blob's through Vue.

In this MR we render the blob viewer Vue app instead of the haml-based viewer when the feature flag is enabled.

MR	status
Add Blob Page to the repository vue app	✅ merged
Add Blob content viewer to the repository app	✅ merged
Use Editor Lite in readonly mode to view blobs	✅ merged
Render blob viewer Vue app	This MR

Note: This MR is part of a bigger effort to refactor the refactor the repository browser to one Vue application, see &5531 (closed) for more details.

Changes in this MR are behind the :refactor_blob_viewer feature flag.

Screenshots

No visual changes are expected as the feature is behind a feature flag.

Does this MR meet the acceptance criteria?

Conformity

• 📋 Does this MR need a changelog?
  • I have included a changelog entry.
  • I have not included a changelog entry because the feature is behind a feature flag.
• Code review guidelines
• Merge request performance guidelines

Availability and Testing

• Tested in all supported browsers

Related to #323200 (closed)