In ct_search, Unexpected Results when Passing "total" to arg `commod_codes`

[ChrisMuir]

Example, showing the current issue:

comtradr::ct_update_databases(commodity_type = "EB02")
vals <- ct_search(reporters = "USA", 
                  partners = "World", 
                  freq = "annual", 
                  start_date = "2015-01-01", 
                  end_date = "2015-12-31", 
                  commod_codes = "TOTAL", 
                  type = "services")
nrow(vals)
#> 0

This query should return a data frame with two rows, not 0.

In ct_search, the default value for the commodity codes arg is "TOTAL", which is meant to mean "all commodities". In the guts of ct_search, the literal string "TOTAL" ends up getting used within the query url ... this works for all of the different "HS" commodity schemes, however for EB02, "TOTAL - all services" has an actual commodity code of 200.

To fix this within ct_search, when "all" or "total" is passed as input to arg commod_codes, I'll have a step that actually looks up the code for either in the current commodity codes db on file.

This issue first came up in #5.

[ChrisMuir]

Fixed via commit cd25402.