Move clone button out of blob header

What does this MR do?

On the snippet view, this MR moves the "Clone" button out of the blob's header and into the global scope of the snippet itself. We need this in order to support multi-file scenario for snippets when we are going to have multiple blobs in the same snippet and hence, it doesn't make sense to have the "Clone" button any visual relationship to any of the blobs.

Screenshots

Before	After

Also, the case when a snippet is not embeddable, yet the Clone button is rendered:

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

References #220799 (closed)