^::foo/ does not trigger cljr-slash

I'd expect typing `^::str/` to insert a `clojure.string` require, but currently it doesn't.

Probably in:

https://github.com/clojure-emacs/clj-refactor.el/blob/cd6b6fb30fc5a429ff209d20af2f2f304937fe99/clj-refactor.el#L1927

One should add something like:

```diff
(1- (point)))
+ (string-remove-prefix "^::")
(string-remove-prefix "::"))))
```

Cheers - V