[OU-ADD] account_credit_control: Rename m2m table and fields

Till v9, old field attributes `rel`, `col1` and `col2` were being
applied to the m2m table. As in v10, old ORM is totally removed, now
we need to put `relation`, `column1` and `column2` attributes for
customizing the m2m relation table.

As no customization, standard names apply, so we need to do the
renamings according to this.

account_credit_control/migrations/10.0.1.0.0/pre-migration.py

@@ -0,0 +1,21 @@
+# Copyright 2021 Tecnativa - Pedro M. Baeza
+# License AGPL-3.0 or later (https://www.gnu.org/licenses/agpl).
+from openupgradelib import openupgrade
+
+
+@openupgrade.migrate()
+def migrate(env, version):
+    openupgrade.rename_tables(
+        env.cr, [(
+            "credit_run_policy_rel",
+            "credit_control_policy_credit_control_run_rel"
+        )]
+    )
+    openupgrade.rename_columns(
+        env.cr, {
+            "credit_control_policy_credit_control_run_rel": [
+                ("run_id", "credit_control_run_id", ),
+                ("policy_id", "credit_control_policy_id"),
+            ]
+        }
+    )