[FIX] payment, payment_custom: uninstall crash of payment modules

Before this commit a constraint between the `ir_ui_view` and
`payment_provider` view made impossible for providers to be
uninstalled. After this commit the constraint is correctly treated.

A similar issue is found on a constraint on the `payment_custom`
module. To fix this and future possible problems we added the
possibility to modify the way providers are uninstalled following
each provider needs.

Task - 3002532

closes odoo/odoo#102951

X-original-commit: 56318826b758f09782c8f67c05a7a46789cff47d
Related: odoo/documentation#2802
Signed-off-by: Antoine Vandevenne (anv) <anv@odoo.com>

addons/payment/models/payment_provider.py

@@ -589,7 +589,23 @@ class PaymentProvider(models.Model):
         :return: None
         """
         providers = self.search([('code', '=', provider_code)])
-        providers.write({
+        providers.write(self._get_removal_values())
+
+    def _get_removal_values(self):
+        """ Return the values to update a provider with when its module is uninstalled.
+
+        For a module to specify additional removal values, it must override this method and complete
+        the generic values with its specific values.
+
+        :return: The removal values to update the removed provider with.
+        :rtype: dict
+        """
+        return {
             'code': 'none',
             'state': 'disabled',
-        })
+            'is_published': False,
+            'redirect_form_view_id': None,
+            'inline_form_view_id': None,
+            'token_inline_form_view_id': None,
+            'express_checkout_form_view_id': None,
+        }

addons/payment_custom/models/payment_provider.py

@@ -71,3 +71,9 @@ class PaymentProvider(models.Model):
                 f'<h4>{_("Communication")}</h4>' \
                 f'<p>{_("Please use the order name as communication reference.")}</p>' \
                 f'</div>'
+
+    def _get_removal_values(self):
+        """ Override of `payment` to nullify the `custom_mode` field. """
+        res = super()._get_removal_values()
+        res['custom_mode'] = None
+        return res