estimate_contrasts() : Report CI adjustment in footnote (and reconsider default)

[bwiernik]

Currently, estimate_contrasts() applies a CI adjustment (straight bonferonni) but does not report it in the results footnote. If the CI is adjusted, we should report that in addition to the p-value adjustment.

d <- transform(mtcars, cyl = factor(cyl))
m <- lm(mpg ~ cyl, data = d)

# CIs are adjusted, but this is not reported in the footnote
modelbased::estimate_contrasts(m)

# No CI adjustment
modelbased::estimate_contrasts(m, adjust = "none")

Do we want to apply an adjustment at all by default? We only do this for estimate_contrasts() and correlation::correlation(), not other functions in the easystats 'verse. That seems a little inconsistent? If we do want an adjustment by default, for estimate_contrasts(), perhaps dunnettx or mvt (or mvt when the number of row is small and dunnettx otherwise) would be better by default than holm because they are less conservative?

See also other issues with adjust: https://github.com/easystats/modelbased/issues/163