dm_get_all_pks() checks the
dm object for set primary keys and
returns the tables, the respective primary key columns and their classes.
One or more table names, as character vector, to return primary key information for. The default
NULLreturns information for all tables.
These dots are for future extensions and must be empty.
A tibble with the following columns:
column name(s) of primary key, as list of character vectors.