Before this commit:
In Email Marketing's Mail Body, The Powerbox is opened below the cursor,
even when there's not enough space between the cursor line and
the window's bottom. As a result, a part of the Powerbox cannot be seen.
After this commit:
Now, the Powerbox opens itself above the cursor line if it's too close to the
window's bottom.
Task-3037435
closesodoo/odoo#108352
X-original-commit: ba888c39716f0226adce993cb08852e21b0376eb
Signed-off-by: David Monjoie (dmo) <dmo@odoo.com>