Create branch 16.0

--HG-- branch : 16.0

data/date_range_type.xml

+<?xml version="1.0" encoding="utf-8" ?>
+<odoo noupdate="1">
+    <record id="period_type" model="date.range.type">
+        <field name="name">Default Period</field>
+        <field name="duration_count">1</field>
+        <!-- MONTHLY = 1 -->
+        <field name="unit_of_time">1</field>
+        <field name="name_expr">f"{date_start.strftime('%Y/%m')}"</field>
+    </record>
+</odoo>