improve warning about change in unique companies after sector split

[cjyetman]

Currently when I run run_match_prioritize(), and more specifically apply_sector_split_to_loans(), with the test loanbooks and data that I have, I get all of these warnings. To be honest, I'm not sure if that's bad (probably, because it's a warning?), I'm not sure how bad that is (e.g. going from 1 to 132 seems dramatic, but maybe that's normal?), and I don't have any idea of how to fix it or what to look at. It would be advantageous to improve this a bit. Additionally, I suspect if this happens to 1 loanbook it's likely to happen in others (?), so when one runs run_match_prioritize() they'll likely get a series of these warnings one after another, and it's not clear which loanbook a given warning message is related to, so maybe we could improve that?

run_match_prioritize(config_path)
#> Warning messages:                                                                             
#> 1: ! Applying the sector split has lead to changes in the number of unique companies covered in
#>   the analysis.
#> ℹ Prior to the split, there was 1 unique company.
#> ℹ After the split, there are 74 unique companies. 
#> 2: ! Applying the sector split has lead to changes in the number of unique companies covered in
#>   the analysis.
#> ℹ Prior to the split, there was 1 unique company.
#> ℹ After the split, there are 84 unique companies. 
#> 3: ! Applying the sector split has lead to changes in the number of unique companies covered in
#>   the analysis.
#> ℹ Prior to the split, there was 1 unique company.
#> ℹ After the split, there are 51 unique companies. 
#> 4: ! Applying the sector split has lead to changes in the number of unique companies covered in
#>   the analysis.
#> ℹ Prior to the split, there was 1 unique company.
#> ℹ After the split, there are 76 unique companies. 
#> 5: ! Applying the sector split has lead to changes in the number of unique companies covered in
#>   the analysis.
#> ℹ Prior to the split, there was 1 unique company.
#> ℹ After the split, there are 115 unique companies. 
#> 6: ! Applying the sector split has lead to changes in the number of unique companies covered in
#>   the analysis.
#> ℹ Prior to the split, there was 1 unique company.
#> ℹ After the split, there are 132 unique companies.