Until now using a groupby on a view containing a reified field added
with studio was not possible.
Because `read_group` uses these pseudofields as simple fields when they
are not actually columns in the table.
With `read`, `write`, `create` and `fields_get` it was already
supported.
This commit solves this problem by ignoring reified fields in an
override of `read_group`
opw-2793148
closesodoo/odoo#87186
X-original-commit: a25e25aeab3ed6aa1af57fac13312346b723dbf8
Signed-off-by: Raphael Collet <rco@odoo.com>