Bug 30824: Improve performance of BatchCommitItems

Bug 30824: Improve performance of BatchCommitItems

This makes two simple changes:
- Limit TransformMarcToKoha to the fields we need
- Pass forward the biblioitemnumber when adding items to a new biblionumber

Profiling with NYTProf I saved ~8-9 seconds importing around 400 bibs/1000 items

Reducing calls in item store to use a passed biblionumber was the largest gain.

To test:
1 - Import some records and items
2 - Verify values etc., revert
3 - Apply patch
4 - Import again
5 - Verify values etc. same as before

Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Joonas Kylmälä <joonas.kylmala@iki.fi>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>