[FIX] purchase: no more bold rows when unreaded messages that won't dissapear

Steps to reproduce:

- Install purchase and discuss.
- Go to the purchase list view.
- You will see the purchase lines in bold.

Issue:

The bold lines are supposed to indicate that we have unreaded messages
in the chatter, but they are not working as expected, and instead it is
mixed with discuss, and they bold line won't dissappear until we send a
message in discuss.

Solution:

We removed from the views the "feature" of showing bold lines as it is
not well implemented, and it is not working as expected. This will avoid
confusion for the clients on not knowing what it is for, and when it's
bold or when it's not. Also this feature was removed in future versions.

Extra info:

If you don't have any lines in bold, and you realize they don't appear
when you send messages through the chatter. The easiest way I found to
test it is removing `cp.channel_id = msg.res_id AND ` from the SQL query
in the code inside `_compute_message_unread`. With this you will see the
bold row whenever you send a message in the chatter, but it won't
dissappear when you open the RfQ.

Forward bot up to saas-15.2.

opw-3185071

closes odoo/odoo#113166

Signed-off-by: William Henrotin (whe) <whe@odoo.com>

addons/purchase/views/purchase_views.xml

@@ -513,10 +513,9 @@
             <field name="model">purchase.order</field>
             <field name="priority" eval="1"/>
             <field name="arch" type="xml">
-                <tree string="Purchase Order" multi_edit="1" decoration-bf="message_unread==True"
+                <tree string="Purchase Order" multi_edit="1"
                       decoration-muted="state=='cancel'" decoration-info="state in ('wait','confirmed')" sample="1">
                     <field name="priority" optional="show" widget="priority" nolabel="1"/>
-                    <field name="message_unread" invisible="1"/>
                     <field name="partner_ref" optional="hide"/>
                     <field name="name" string="Reference" readonly="1"/>
                     <field name="date_order" invisible="not context.get('quotation_only', False)" optional="show"/>
@@ -544,13 +543,12 @@
             <field name="model">purchase.order</field>
             <field name="priority" eval="10"/>
             <field name="arch" type="xml">
-                <tree string="Purchase Order" multi_edit="1" decoration-bf="message_unread==True"
-                      class="o_purchase_order" js_class="purchase_list_dashboard" sample="1">
+                <tree string="Purchase Order" multi_edit="1" class="o_purchase_order"
+                      js_class="purchase_list_dashboard" sample="1">
                     <header>
                         <button name="action_create_invoice" type="object" string="Create Bills"/>
                     </header>
                     <field name="priority" optional="show" widget="priority" nolabel="1"/>
-                    <field name="message_unread" invisible="1"/>
                     <field name="partner_ref" optional="hide"/>
                     <field name="name" string="Reference" readonly="1" decoration-bf="1"/>
                     <field name="date_approve" invisible="context.get('quotation_only', False)" optional="show"/>
@@ -577,8 +575,7 @@
             <field name="name">purchase.order.view.tree</field>
             <field name="model">purchase.order</field>
             <field name="arch" type="xml">
-                <tree decoration-bf="message_unread==True"
-                    decoration-muted="state=='cancel'"
+                <tree decoration-muted="state=='cancel'"
                     decoration-info="state in ('wait','confirmed')"
                     string="Purchase Order"
                     class="o_purchase_order"
@@ -587,7 +584,6 @@
                         <button name="action_create_invoice" type="object" string="Create Bills"/>
                     </header>
                     <field name="priority" optional="show" widget="priority" nolabel="1"/>
-                    <field name="message_unread" invisible="1"/>
                     <field name="partner_ref" optional="hide"/>
                     <field name="name" string="Reference" readonly="1" decoration-bf="1"/>
                     <field name="date_approve" widget="date" invisible="context.get('quotation_only', False)" optional="show"/>