tdf#153806 cui: Deduplicate code for special char dialog handlers

Various handlers for `m_xShowSet` and `m_xSearchSet` are
the same, except that they operate on the different objects.

However, since a pointer to the `SvxShowCharSet`/`SvxSearchCharSet`
is passed as an argument to the handler, use that
and reuse the existing handlers instead of duplicating them.

Also extract a `SvxCharacterMap::insertSelectedCharacter` method
from the `CharDoubleClickHdl`, since that will be reused elsewhere
in a follow-up commit for tdf#153806.

Change-Id: I14e8e7fd7add33f86fa0246c65927ceb88bb7899
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/149919
Tested-by: Jenkins
Reviewed-by: Michael Weghorn <m.weghorn@posteo.de>

0 files changed, 0 insertions, 0 deletions