[FIX] subscription_oca: product-subscription_template company issues

Make company required on subscription_template.

Make subcription_template_id a company-dependent field
on product_template.

subscription_oca/migrations/14.0.2.0.0/post-migrate.py

@@ -0,0 +1,14 @@
+from openupgradelib import openupgrade
+
+
+@openupgrade.migrate()
+def migrate(env, version):
+    openupgrade.convert_to_company_dependent(
+        env,
+        "product.template",
+        "old_subscription_template_id",
+        "subscription_template_id",
+    )
+    openupgrade.drop_columns(
+        env.cr, [("product_template", "old_subscription_template_id")]
+    )