Add utils-tidy-eval to package

[spencerpease]

This utils file will import things needed for proper tidy-eval use, such as .data and :=, which means we don't have to import them in any other function.

It can be added with usethis::use_tidy_eval().

References

• https://usethis.r-lib.org/reference/tidyverse.html
• https://github.com/r-lib/usethis/blob/master/inst/templates/tidy-eval.R