Add VO-DrugBank predictions and curations

[cthoyt]

• First pass with canned workflow
• Create a more custom workflow for doing lexical matchings, since a lot of the time, there are many components mapped to the upper level vaccine in DrugBank

For example, vo:0000015 (Boostrix), a booster immunization against tetanus, diphtheria and pertussis, gets mapped to the following:

• drugbank:DB10583 Clostridium
• drugbank:DB10584 Corynebacterium diphtheriae toxoid antigen (formaldehyde inactivated)
• drugbank:DB10788 Bordetella pertussis filamentous hemagglutinin antigen (formaldehyde inactivated)
• drugbank:DB10789

This doesn't really make sense in Biomappings since these are part-whole relationships. VO has these to some extent, so maybe they can be used to identify the more specific parts.