`@name` should be escaped as well

Currently aliases are escaped, but names are not. Here is a test case:

``` r
roc <- rd_roclet()
test_that("names escaped, not quoted", {
  out <- roc_proc_text(roc, "
    #' Title
    '%a%' <- function(x, y) x + y")[[1]]
  expect_equal(format(get_tag(out, "name")), "\\name{\\%a\\%}\n")
})
```
