Move synonyms we don't want from a CURIE-based blocklist to a synonym-based blocklist

[gaurav]

For example, we've blocked "Down syndrome" from NameRes entirely because one of its synonyms -- "mongoloidism" -- is quite impolite. It would be better if we could block this synonym without have to block the entire term. There are two ways we could implement this:

1. Instead of asking NameRes to download the blocklist as a list of CURIEs, we can download the blocklist as a list of synonym patterns (e.g. "mongoloid*"), and then all synonyms are checked against that list before being returned to the user.
2. Move this pattern matching into Babel, so that synonyms like "mongoloidism" are removed entirely at the source (or, alternatively, put into a separate synonym list so we can include them if necessary... but that will make our indexes bigger).

Something like this may also be a way to implement MVP-specific checklists (#120).

Using Babel would involve:

• Figuring out a "blocklist" of individual synonyms that we want to exclude, including variants.
• Filtering those out when using the Synonym
• Write up some kind of report of all the synonyms we've removed, so we can make sure we don't go overboard or overbroad.