Internal function that calculates the `overview_tab` for data.frame objects
Arguments
- dat2
Your data set
- dat
Your data set
- id
Scope (e.g., country codes or individual IDs)
- time
Time (e.g., time periods given by years, months, ...). There are three options to add a date variable: 1) Time can be a character vector containing **one** time variable, 2) a time variable following the YYYY-MM-DD format, or 3) or a list containing multiple time variables (`time = list(year = NULL, month = NULL, day = NULL)`).