Catch single-quotes FUN when looking for character.only=TRUE in library_call_linter()

[MichaelChirico]

          This is to catch `lapply(pkgs, "library", character.only = TRUE)`?

Is that worth it? If yes, we should catch lapply(pkgs, 'library', character.only = TRUE) too.

Originally posted by @AshesITR in #2306 (comment)