SwNumRule: add getter / setter for InteropGrabBag

Change-Id: I6f76dbfd806139f141c054dccb0884be32511e06
sw: add InteropGrabBag for list styles

Change-Id: I2881a507d71aad10e39272141b5d63c6e39e2cc9
Introduce MSWordStyles::GetSwNumRule()

This is similar to GetSwFmt(), but for list styles.

Change-Id: I5c198c786e0c73c83430bd60b91d0ef85c7a49fc
DOCX filter: handle numbering style's qFormat, rsid and friends

Change-Id: Ia261995b98e2108ab673c7b240a1aa822d3db96e