Resolve "Move files in the Web IDE"

EE port for https://gitlab.com/gitlab-org/gitlab-ce/merge_requests/25431

What does this MR do?

Improve the Rename button behavior to support moving files and folders.

Initial	Rename (basename selected)	Renamed

• The Rename modal should show the full path of the file or directory
• The last component of the path should be highlighted by default so that the file can be quickly renamed without moving
• When moving a file
  • if a file already exists at that path, show an error
  • if the target directory doesn't exist, silently create the directory path and move the file
• When moving a directory
  • if the target directory already exists, show an error
  • if the target directory doesn't exist, silently create the necessary directory and move the file

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated via this MR
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Tested in all supported browsers
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.
• Security reports checked/validated by reviewer

Closes #49397