[FIX] web_unsplash: save image for res_model

Go on the website, create a new product from there
Click on the image to change it, select an unsplash image

Save your product.

Beforer this commit, the image wasn't saved because the qweb field image
did not know what to do with /unsplash/ urls

After this commit, the image is saved on the product (or any object...)

OPW 1936191

closes odoo/odoo#31328

addons/web_unsplash/models/__init__.py

@@ -3,3 +3,4 @@
 
 from . import res_config_settings
 from . import res_users
+from . import ir_qweb

addons/web_unsplash/models/ir_qweb.py

@@ -0,0 +1,26 @@
+from werkzeug import urls
+
+from odoo import models, api
+
+
+class Image(models.AbstractModel):
+    _inherit = 'ir.qweb.field.image'
+
+    @api.model
+    def from_html(self, model, field, element):
+        url = element.find('img').get('src')
+        url_object = urls.url_parse(url)
+
+        if url_object.path.startswith('/unsplash/'):
+            res_id = element.get('data-oe-id')
+            if res_id:
+                res_id = int(res_id)
+                res_model = model._name
+                attachment = self.env['ir.attachment'].search([
+                    ('res_model', '=', res_model),
+                    ('res_id', '=', res_id),
+                    ('url', '=', url_object.path),
+                ], limit=1)
+                return attachment.datas
+
+        return super(Image, self).from_html(model, field, element)