[FIX] pos_mercury: revert of 48b3893b

The previous change was done to solve a case of duplicated xmlids in
v12. By some confusion, both xmlids were changed in separated
commits. This new commit returns the original xmlid of one and assures
to avoid more confusions by adding 'settings' to the other.

Closes odoo/odoo#36885

closes odoo/odoo#37755

Signed-off-by: Martin Trigaux (mat) <mat@odoo.com>

addons/pos_mercury/views/pos_config_setting_views.xml

 <?xml version="1.0" encoding="utf-8"?>
 <odoo>
-    <record id="res_config_view_form_inherit_pos_mercury" model="ir.ui.view">
+    <record id="res_config_settings_view_form_inherit_pos_mercury" model="ir.ui.view">
         <field name="name">res.config.form.inherit.mercury</field>
         <field name="model">res.config.settings</field>
         <field name="inherit_id" ref="point_of_sale.res_config_settings_view_form"/>

addons/pos_mercury/views/pos_config_views.xml

 <?xml version="1.0" encoding="utf-8"?>
 <odoo>
-    <!-- TODO the inherit for
-         point_of_sale.res_config_settings_view_form in this module
-         uses the pos_config_view_form_inherit_pos_mercury xml id
-         already. It should be renamed to
-         res_config_settings_view_form_inherit_pos_mercury. -->
-    <record id="pos_config_view_form_inherit_pos_mercury_2" model="ir.ui.view">
+    <record id="pos_config_view_form_inherit_pos_mercury" model="ir.ui.view">
         <field name="name">pos.config.form.view.inherit.mercury</field>
         <field name="model">pos.config</field>
         <field name="inherit_id" ref="point_of_sale.pos_config_view_form"/>