Utility function to check that user provided "keys" aren't listed as a problem variable of the current list of issues.
assert_valid_keys(COMPARE, KEYS, component, msg)(list)
A named list of which each element is a data.frame with the
column VARIABLE
(character)
name of key variables to check to make sure they don't contain
any issues
(character)
name of the component within COMPARE to check against
(character)
error message to print if any of KEYS are found within
COMPARE[component]$VARIABLE