A name for each file that is unique within one data_check run
Source:R/data_check_helpers.R
dot-data_source_keys.Rddata_check keeps every table it reads, and every column and finding of
it, under this name (source_file), and codebook_check looks the tables
up by it. The file name alone is not unique: a measurement repository can
hold a log.csv in every scan folder, and keyed by name only one of them
was kept and checked. The name is the file name when no other file has it,
so nothing changes for most repositories; else the file's path in the
repository; and where even that repeats (the same path in two
repositories), the repository's name in front.