[IMP] base_action_rule: introduce methods `_filter_pre` and `_filter_post`
[IMP] base_action_rule: introduce methods `_filter_pre` and `_filter_post`

Those methods improve the readability of the code.

hip-odoo/odoo,sysadminmatmoz/OCB,storm-computers/odoo,laslabs/odoo,ygol/odoo,bplancher/odoo,storm-computers/odoo,microcom/odoo,sysadminmatmoz/OCB,bplancher/odoo,dfang/odoo,sysadminmatmoz/OCB,stephen144/odoo,Elico-Corp/odoo_OCB,stephen144/odoo,optima-ict/odoo,hip-odoo/odoo,microcom/odoo,microcom/odoo,dfang/odoo,dfang/odoo,laslabs/odoo,ygol/odoo,microcom/odoo,laslabs/odoo,storm-computers/odoo,stephen144/odoo,sysadminmatmoz/OCB,sysadminmatmoz/OCB,hip-odoo/odoo,optima-ict/odoo,sysadminmatmoz/OCB,ygol/odoo,ygol/odoo,Elico-Corp/odoo_OCB,laslabs/odoo,Elico-Corp/odoo_OCB,storm-computers/odoo,storm-computers/odoo,laslabs/odoo,optima-ict/odoo,hip-odoo/odoo,optima-ict/odoo,optima-ict/odoo,microcom/odoo,dfang/odoo,Elico-Corp/odoo_OCB,stephen144/odoo,optima-ict/odoo,storm-computers/odoo,hip-odoo/odoo,bplancher/odoo,sysadminmatmoz/OCB,stephen144/odoo,microcom/odoo,bplancher/odoo,stephen144/odoo,dfang/odoo,ygol/odoo,bplancher/odoo,bplancher/odoo,hip-odoo/odoo,dfang/odoo,ygol/odoo,ygol/odoo,Elico-Corp/odoo_OCB,Elico-Corp/odoo_OCB,laslabs/odoo