tdf#132776 sw UI: make unique names for custom hatch and gradient
This has already been done in sd, so just copy the idea
and adapt it to fit in the sw environment.
This fixes LO 6.3.4 regression from 7.0
commit
53c474633c4e658f096669fb0225d751a5701aaf.
This reason for this is noted in one of those commits:
> However tdf#99908 shows that ODF import doesn't like anonymous
> gradients. This is a bug in xmloff style import and should eventually
> be fixed there. Here we implement the same band-aid solution
> tdf#99908 implements for Impress sidebar
Change-Id: I4437ac97b6aa97f2cd27a10c3d593dc97d24e9c1
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/117594
Tested-by: Jenkins
Reviewed-by: Justin Luth <justin_luth@sil.org>