[FIX] web_editor: don't display option if target matches data-exclude

Since [this commit], it's now possible to edit a media when it's in a
parent that is not editable thanks to `o_editable_media` class.
Unfortunately, these changes make the new class bypass the potential
`data-exclude` defined in the XML option declaration. So if the target
looks like that:
```html
<img class="o_editable_media odoo"/>
```
and the XML option declaration has a `data-exclude=".odoo"`, the option
will still be displayed. This commit corrects the way the
`o_editable_media` class works, so that it only bypasses the
`.o_not_editable` but not the entire exclude.

[this commit]: https://github.com/odoo/odoo/commit/580f1b77ce0b96b7efbf83a0ccdf6979bbf0e904



task-3476644

closes odoo/odoo#133594

X-original-commit: f73734557116a348ac14b2724e1380546192ca12
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>
Signed-off-by: Guillaume Dieleman (gdi) <gdi@odoo.com>