Bug 21908: Add biblio_metadata to rebuild_zebra.pl tables

Bug 21908: Add biblio_metadata to rebuild_zebra.pl tables

Zebra indexing script misc/migration_tools/rebuild_zebra.pl as a table arg to allow filtering.
It is missing biblio_metadata to allow filtering on MARCXML with ExtractValue.

Test plan :
1) Be sur you have a biblio record with biblionumber 1
2) Run misc/migration_tools/rebuild_zebra.pl -h
3) You see : --table specify a table (can be items, biblioitems, biblio, biblio_metadata) to retrieve biblionumber to index.
4) Run misc/migration_tools/rebuild_zebra.pl -v -b --table biblio_metadata --where="biblio_metadata.biblionumber=1"
5) Check you dont have SQL errors

Signed-off-by: Pierre-Marc Thibault <pierre-marc.thibault@inLibro.com>
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>