[FIX] web: avoid double margins after Many2ManyTags fields
[FIX] web: avoid double margins after Many2ManyTags fields

Before this commit, there was too much space after Many2ManyTags
fields. This was due to the fact that a many2one is embedded in the
many2manytags widget. Therefore, the css rule who add margin-bottom
was applied twice.
e.g.: Tags field in project task form view

To fix this, we remove the margin-bottom from the children widgets.

Note: This bug is not a big deal in previous versions but in 12.2
margins between fields has been increased in mobile and  we clearly
saw this issue.

Task ID: 1944884

closes odoo/odoo#32193

Signed-off-by: Pierre Paridans <8fa739e2f9d7b5a816d8ae6bcac8922d88e25459@users.noreply.github.com>
ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo