Remove lacros tooltip code from //ui/views

Lacros is deprecated. Remove tooltip code from //ui/views and
also remove tests from test files.

1) Remove code under IS_CHROMEOS_LACROS including call sites and
impls.
2) Remove *_lacros.cc/.h files.
3) Clean up fwd decl and includes (like unnecessary fwd decls while
using objects by value, etc).
4) Remove helper calls (getters/setters) added for tooltip code for
lacros.
5) Remove redundant functions like "UseServerSideTooltip" that has
never been used.

Bug: 374073840, 373971535
Change-Id: Id76c1ffa3827422addba0bad9f241630d8e4e781
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5961738
Reviewed-by: Peter Boström <pbos@chromium.org>
Reviewed-by: Thomas Anderson <thomasanderson@chromium.org>
Reviewed-by: Hidehiko Abe <hidehiko@chromium.org>
Commit-Queue: Maksim Sisov <msisov@igalia.com>
Cr-Commit-Position: refs/heads/main@{#1374491}