update `fpr::fpr_table_fish_site` to be able to process multiple sites and make caption text flexible

[NewGraphEnvironment]

Gershwin in Skeena 2024 is a good example ofwhere this keeps things clean

just swap == for %in%

[NewGraphEnvironment]

may as well make the caption default be as before but as a param so we can swap in text like "Fish sampling site summary for 125231 for 2023." (for cases where we have seperate tables for each year)