Use 'Highlighting' also on Character Dialog.

(cherry picked from commit 3588a04f)

Options: Background -> Highlighting

(cherry picked from commit b47151f5)

Search By Format: Background -> Highlighting

(cherry picked from commit 16d202f2)

Make this string localizable

(cherry picked from commit a676ad5e)

Change-Id: Ifa48799bb9e415d17f4e323008fac57270bae34b
Reviewed-on: https://gerrit.libreoffice.org/16322Reviewed-by: Adolfo Jayme Barrientos <fitojb@ubuntu.com>
Tested-by: Adolfo Jayme Barrientos <fitojb@ubuntu.com>