Error message improvements

[DavisVaughan]

its not it's

library(slider)

slide(1, identity, .before = -1)
#> Error: When `.before` (-1) is negative, it's absolute value (1) cannot be greater than `.after` (0).

Incompatible size updates: https://github.com/DavisVaughan/slider/pull/186#discussion_r1022893282 Incompatible type updates: https://github.com/DavisVaughan/slider/pull/186#discussion_r1022895727

Reporting location context first:

• https://github.com/DavisVaughan/slider/pull/186#discussion_r1022894110
• https://github.com/DavisVaughan/slider/pull/186#discussion_r1022894667