use a strong-typedef template to give which IDs a type, which we can
carry around to do a
(a) little bit more convenience when Get()'ing them
and
(b) a little bit of enforcement of which PoolItem subclass each ID uses

Fix a bug in casting EE_PARA_BULLETSTATE to the wrong subclass
in AccessibleEditableTextPara::_correctValues

Change-Id: I015ce8b3b0f6d21308af182afa3caf122c877a5b
Reviewed-on: https://gerrit.libreoffice.org/44587Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>