Re-implement run_hist with new bmo superpowers

The 'history' mode allows incrementally creating item list by typing
items directly to dmenu.

Also, stderr and stdout are now kept automatically for all menus.

dotfiles/config/bmo/menu.ini

 [menu._default_]
 
-    name        = status
     selector    = bmo dmenu
 
 [menu.def.uris]
 
 [menu.def.run_hist]
 
-    generator   = tac .local/share/bmo/menu/run_hist.history | awk '!seen[$0]++'
-    consumer    = tee -a .local/share/bmo/menu/run_hist.history | sed 's/$/ \&/' | sh - >> .local/share/bmo/menu/run_hist.out 2>&1
+    mode = history
+    consumer = sed 's/$/ \&/' | sh -
 
 [menu.def.browsers]