[FIX] l10n_sa_edi: missing reason when reversing entries

With a SA company setup
Open a jounrnal entry
Hit 'Reverse Entry' > Reverse
Error: "For Credit/Debit notes issued in Saudi Arabia, you need to
specify a Reason"

This occurs because with SA localization we need to provide a reason for
move reversal but by default the reason field is invisible for journal entries

opw-3789732

closes odoo/odoo#157996

Signed-off-by: Claire Bretton (clbr) <clbr@odoo.com>

addons/l10n_sa_edi/__manifest__.py

@@ -25,6 +25,7 @@ E-invoice implementation for the Kingdom of Saudi Arabia
         'data/ubl_21_zatca.xml',
         'data/res_country_data.xml',
         'wizard/l10n_sa_edi_otp_wizard.xml',
+        'wizard/account_move_reversal_views.xml',
         'views/account_tax_views.xml',
         'views/account_journal_views.xml',
         'views/res_partner_views.xml',

addons/l10n_sa_edi/wizard/account_move_reversal_views.xml

@@ -0,0 +1,16 @@
+<?xml version="1.0" encoding="utf-8"?>
+<odoo>
+    <data>
+        <record id="view_account_move_reversal_inherit_l10n_sa_edi" model="ir.ui.view">
+            <field name="name">account.move.reversal.form.inherit.l10n_sa_edi</field>
+            <field name="inherit_id" ref="account.view_account_move_reversal"/>
+            <field name="model">account.move.reversal</field>
+            <field name="arch" type="xml">
+                <field name="reason" position="replace">
+                    <field name="country_code" invisible="1"/>
+                    <field name="reason" string="Reason" invisible="move_type == 'entry' and country_code != 'SA'" required="country_code == 'SA'"/>
+                </field>
+            </field>
+        </record>
+    </data>
+</odoo>