editor/evil: port vim-unimpaired keybinds

Adds these keys, inspired by tpope/vim-unimpaired:

[ SPC, ] SPC (or [o, ]o)
  Add COUNT blank lines above/below the cursor
[f, ]f
  Visit previous/next file in current folder, alphabetically
[u, ]u
  Url encode/decode operators
[y, ]y
  C-string-style escaping/unescaping operators (escapes quotes,
  backslashes and control characters)
[x, ]x
  XML entity encoding/decoding operators (only if :lang web is enabled)
[F, ]F
  Focus previous/next frame (decided this is better than ]t/[t which is
  being used by hl-todo-{next,previous})

We already had gp and ]b/[b (buffers).

We're not going to port ]e/[e because it is redundant with ddp/ddP or gx
(evil-exchange). I also think these keybinds are better suited to
{next,previous}-error.

modules/editor/evil/autoload/evil.el

@@ -31,16 +31,6 @@
   (evil-normal-state)
   (evil-visual-restore))
 
-;;;###autoload
-(defun +evil/reselect-paste ()
-  "Return to visual mode and reselect the last pasted region."
-  (interactive)
-  (cl-destructuring-bind (_ _ _ beg end &optional _)
-      evil-last-paste
-    (evil-visual-make-selection
-     (save-excursion (goto-char beg) (point-marker))
-     end)))
-
 ;;;###autoload
 (defun +evil/paste-preserve-register ()
   "Call `evil-paste-after' without overwriting the clipboard (by writing to the