Add a "Did you mean...?" help message for columns

[amanda-hi]

Currently, the user must run columns() to view a list of all available data types (columns) in the database. I myself often run into the problem of using a column value of "ENTREZ" (incorrect) instead of "ENTREZID" (correct), or perhaps using "ENSEMBLID" (incorrect) instead of "ENSEMBL" (correct). I think must run columns(SomaScan.db) to view & identify the correct values.

It would be nice to output a "Did you mean...?" message after the user provides an incorrect column name, with a grep() performed under the hood to list all similar columns names/potential matches. This will be faster than running a separate columns() call, and hopefully could be implemented for keytypes() as well.