[FIX] repair: fix html formatting in narration

Followup of odoo/odoo@cb4f597410 and odoo/enterprise@971f3ed9ae

We have converted string into markup string in repair as we cannot concatenate
strings directly to Markup string. And if we try to do it we will see the
html elements '<br/>' in field value, so we have to convert '<br/>' string
into markup language to avoid this.

Also avoid adding pseudo-void html content in narration.

LINKS

Task Id-2558824
PR odoo/odoo#74795
PR odoo/enterprise#20117

addons/repair/models/repair.py

@@ -3,9 +3,11 @@
 from collections import defaultdict
 from random import randint
 
+from markupsafe import Markup
+
 from odoo import api, fields, models, _
 from odoo.exceptions import UserError, ValidationError
-from odoo.tools import float_compare
+from odoo.tools import float_compare, is_html_empty
 
 
 class StockMove(models.Model):
@@ -344,7 +346,7 @@ class Repair(models.Model):
                     'partner_id': partner_invoice.id,
                     'partner_shipping_id': repair.address_id.id,
                     'currency_id': currency.id,
-                    'narration': narration,
+                    'narration': narration if not is_html_empty(narration) else '',
                     'invoice_origin': repair.name,
                     'repair_ids': [(4, repair.id)],
                     'invoice_line_ids': [],
@@ -358,10 +360,11 @@ class Repair(models.Model):
                 invoice_vals = current_invoices_list[0]
                 invoice_vals['invoice_origin'] += ', ' + repair.name
                 invoice_vals['repair_ids'].append((4, repair.id))
-                if not invoice_vals['narration']:
-                    invoice_vals['narration'] = narration
-                else:
-                    invoice_vals['narration'] += '<br/>' + narration
+                if not is_html_empty(narration):
+                    if  is_html_empty(invoice_vals['narration']):
+                        invoice_vals['narration'] = narration
+                    else:
+                        invoice_vals['narration'] += Markup('<br/>') + narration
 
             # Create invoice lines from operations.
             for operation in repair.operations.filtered(lambda op: op.type == 'add'):