[IMP] mail: limit next / previous activities to same kind
[IMP] mail: limit next / previous activities to same kind

When creating an activity type flow using recommended next activities we
should limit the available activity types by model. They should be either
generic either of the same kind. Otherwise you could have inconsistent
results.

This commit is linked to task ID 1844644 and PR #25843.

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo