WillemSleegers/tidystats: tidystats 0.7

Changes

• Removed the rlang, checkmate, stringr, readr, purrr, tibble, dplyr, and tidyr dependencies.
• Added a by argument to describe_data() and count_data() for grouping data by one or more variables.

Documentation

• Added a Microsoft Word add-in article and a privacy statement article to the pkgdown website.
• Renamed the "Reusing statistics" vignette to "Converting statistics to a data frame".

Internal changes

• Added internal string helper functions (remove_string, detect_string, extract_string) to replace stringr functionality.
• Added internal data frame helper functions (dots_to_names, group_names, stack_rows) to replace dplyr, tidyr, and purrr functionality.
• Rewrote all tests to use direct value comparisons instead of golden JSON files, removing the dependency on stored reference data.