Add a command to detect duplicates

[hampelm]

Once we have the CSV, we should check if any of the grants are obviously duplicates.

Command: npm run check knight

To start, we can just grab the list of all grants made by the funder (since we know that ID is good) -- that way we don't have to depend on #1.

Heuristics:

• Same grant amount as existing grant
• Same grant start and/or end date as an existing grant
• Same / similar name (maybe use a textual similarity function)

If a match is found, we should add a duplicate column, maybe with a score (0, 1, 2, something like that) and a link to the potential duplicate(s)