Move dependency of gr-comment, which was forgotten

gr-comment is the only element that depends on this, and does so using a
relative HTML import, so it makes sense to move this file as well,
unbreaking the import.

Change-Id: I5c0c42654d4202b9cdd616d34824e266a56e08b6
diff --git a/polygerrit-ui/app/elements/diff/gr-confirm-delete-comment-dialog/gr-confirm-delete-comment-dialog.html b/polygerrit-ui/app/elements/shared/gr-confirm-delete-comment-dialog/gr-confirm-delete-comment-dialog.html
similarity index 100%
rename from polygerrit-ui/app/elements/diff/gr-confirm-delete-comment-dialog/gr-confirm-delete-comment-dialog.html
rename to polygerrit-ui/app/elements/shared/gr-confirm-delete-comment-dialog/gr-confirm-delete-comment-dialog.html
diff --git a/polygerrit-ui/app/elements/diff/gr-confirm-delete-comment-dialog/gr-confirm-delete-comment-dialog.js b/polygerrit-ui/app/elements/shared/gr-confirm-delete-comment-dialog/gr-confirm-delete-comment-dialog.js
similarity index 100%
rename from polygerrit-ui/app/elements/diff/gr-confirm-delete-comment-dialog/gr-confirm-delete-comment-dialog.js
rename to polygerrit-ui/app/elements/shared/gr-confirm-delete-comment-dialog/gr-confirm-delete-comment-dialog.js