[FIX] website_blog: make twitter share string translatable

Previously the default message when sharing a blog article was
hardcoded, meaning it was always in English and not translatable, this
commit fixes that.

Closes https://github.com/odoo/odoo/issues/31173


task-2369420

closes odoo/odoo#62070

X-original-commit: 7e7a1edf702e070cf3f690946e5cda90f21a88d8
Signed-off-by: Quentin Smetz (qsm) <qsm@odoo.com>