fix R CMD CHECK notes + remove unused suggests + remove Hmisc dependency

[olivroy]

• Remove unused imports and suggests
• Remove Hmisc dependency (only one function used, now inlined)
• Correct links in man
• Correct lost braces warnings
• Use NEWS.md for nicer formatting
• Uncomment tests (but skip them on CRAN)
• Use testthat 3rd edition

Some examples fail with ERROR 400, but I can't figure out why.

I had to import the tidyr package, because I couldn't find where the replace_na() call came from. I assumed it was tidyr::replace_na()