vim, vim-core: remove packages from portage-stable

The upstream version of vim and vim-core assume the data directory to be
`/usr/share/...` and install various artifacts under that directory.
However in the test and dev image the default installation directory is
`/usr/local/share/...` and the artifacts should be installed there.
While we figure out a long-term solution we should configure vim and
vim-core to use the correct data directory. Since this requires changes
to the ebuild file, we need to move vim and vim-core to
chromeos-overlay.

BUG=b:249339147
TEST=See dependent CL.

Change-Id: I2adf03925b783a1da9430c09df2a3bd5664d2503
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/overlays/portage-stable/+/4562366
Tested-by: Cheng Yueh <cyueh@chromium.org>
Reviewed-by: Phoebe Wang <phoebewang@chromium.org>
Commit-Queue: Cheng Yueh <cyueh@chromium.org>
12 files changed