fix(paste): improve repeating of pasted text (#30438)

- Fixes 'autoindent' being applied during redo.
- Makes redoing a large paste significantly faster.
- Stores pasted text in the register being recorded.

Fix #28561

src/nvim/terminal.c

@@ -748,6 +748,10 @@ static int terminal_execute(VimState *state, int key)
     }
     break;
 
+  case K_PASTE_START:
+    paste_repeat(1);
+    break;
+
   case K_EVENT:
     // We cannot let an event free the terminal yet. It is still needed.
     s->term->refcount++;