[FIX] web, *: fix the grab cursor not working on all browsers

*: web_editor, pos_restaurant

The grab cursor is currently not working on all browsers (at least
Chrome Linux). The fallback rule does not even work, meaning that if
you type:

```
cursor: move;
cursor: grab;
```

Those browsers does not even use "move" as they see "grab" as valid but
use the "default" cursor.

This commit replaces our "grab" uses with a local cursor ensuring it
works.

Related to task-2431469

closes odoo/odoo#82060

Related: odoo/enterprise#23175
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>