[FIX] web_editor: clear format not working properly

Before this commit:

The text moves back to the left side on remove format even if the direction rtl
is applied.

After this commit:

The text will not move to the left side on remove format if the direction rtl is
applied.

task-3482193

closes odoo/odoo#134240

Signed-off-by: David Monjoie (dmo) <dmo@odoo.com>