Revert "[bookmarks] Add empty-state view as an item type"

This reverts commit e4aecf08.

Reason for revert: Bug in SLL blocking beta.

Original change's description:
> [bookmarks] Add empty-state view as an item type
>
> - Add new view type for the empty state.
> - Remove SelectableListLayout-driven empty state code.
> - Populate the new list type when there are no bookmarks
>
> Bug: 41481889
> Change-Id: I543b5b1ec6b256d4f108f96aebd2d3ecd83a1fd5
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5618133


> Code-Coverage: findit-for-me@appspot.gserviceaccount.com <findit-for-me@appspot.gserviceaccount.com>
> Reviewed-by: Sky Malice <skym@chromium.org>
> Commit-Queue: Brandon Wylie <wylieb@google.com>
> Cr-Commit-Position: refs/heads/main@{#1313137}

Bug: 41481889
Change-Id: Ia976a7cc936bcb17ce67410cbb39a561219ea322
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5622718


Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Auto-Submit: Brandon Wylie <wylieb@google.com>
Reviewed-by: Sky Malice <skym@chromium.org>
Commit-Queue: Sky Malice <skym@chromium.org>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Cr-Commit-Position: refs/heads/main@{#1313524}