Added the basic Snippet Blob View with Blob Embeddable

What does this MR do?

This MR is part of a larger effort of refactoring Snippet view into Vue and introduces the basic Snippet Blob View component that, for now, consists of only the new Blob Embeddable component (that is part of this MR as well).

Since this component is still behind the feature flag and does not constitute the full feature on its own, there's no changelog entry and, instead, the MR is properly marked with ~backstage

	Before	After
Embedding
Sharing

Screenshots

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

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• Label as security and @ mention @gitlab-com/gl-security/appsec
• The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• Security reports checked/validated by a reviewer from the AppSec team

References #34820 (closed)