Directory check
Details
Check that
The user knows that the data will not be saved if
dir = NULL
.The directory exists if it can be created.
The function fails if the directory cannot be created.
Note: this function was copied from the nwfscSurvey package: https://github.com/pfmc-assessments/nwfscSurvey/blob/main/R/check_dir.R rather than adding an additional dependency on that package.