Takes parts of a file name, info, and folder and creates a full path
construct_rcreds_file_full_path(file_name = getOption("rcreds.file_name",
default = ".credentials.creds"), folder = get_default_rcreds_folder(DB =
DB), info.file_name = "", DB = FALSE)
string, cannot be empty Filename with extension. Default is '.credentials.creds'
string, cannot be empty Where file will be stored
string, can be empty. Prepended to file_name.
TRUE/FALSE flag. Is the folder for the db credentials functions?
Defaults to: FALSE
The full file path