Move ImportedBookmarkEntry to components/

This CL moves the 2 following files:
- imported_bookmark_entry.h
- imported_bookmark_entry.cc
from "chrome/common/importer/"
to "components/user_data_importer/common/".

The CL itself is noop, it is only adjusting the
code for the file location and namespace changes.

Bug: 407587751
Change-Id: I6fa486ff92cdd2d36a3aeb879111d90c518b0974
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6578818
Commit-Queue: Colin Blundell <blundell@chromium.org>
Reviewed-by: Ken Buchanan <kenrb@chromium.org>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Auto-Submit: Alexis Hétu <sugoi@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1465477}