include some globbing helper

[jmbarbone]

something like what's implemented in fs::dir_ls()

glob <- function(x, glob = NULL, regexp = NULL, invert = FALSE, ...) {
  if (!is.null(glob)) {
    if (!is.null(regexp)) {
      stop("either `glob` or `regexp` should be NULL", call. = FALSE)
    }
    regexp <- utils::glob2rx(glob)
  }

  if (!is.null(regexp)) {
    params <- list(...)
    params$pattern <- regexp
    params$x <- x
    params$value <- TRUE
    params$invert <- isTRUE(invert)
    x <- do.call(grep, params)
  }

  x
}