[FIX] web: fix export m2m fields on using group_by

Export tool is based on ORM method `_export_rows`. The method has special
processing of m2m fields when user checked *Import compatible* option [1].
Before this commit the negative value of `import_compatible` parameter wasn't
passed when data are exported in grouping mode. This led to empty values in m2m
fields.

STEPS:
* Order some products via website and pay via wire transfer
* Open Orders menu in backend
* group order by any field
* expand group with the order
* add field *Transactions/Acquirer/Display Name*

[1]: https://github.com/odoo/odoo/blob/b28c44a38698018ebbbc420f6567c17b2b97c279/odoo/models.py#L894-L914

opw-2864737

closes odoo/odoo#110151

X-original-commit: 6647ac83467207f4f4ef23aac96ebaf5333b967b
Signed-off-by: Ivan Elizaryev (iel) <iel@odoo.com>

addons/web/controllers/export.py

@@ -469,7 +469,7 @@ class ExportFormat(object):
         model, fields, ids, domain, import_compat = \
             operator.itemgetter('model', 'fields', 'ids', 'domain', 'import_compat')(params)
 
-        Model = request.env[model].with_context(**params.get('context', {}))
+        Model = request.env[model].with_context(import_compat=import_compat, **params.get('context', {}))
         if not Model._is_an_ordinary_table():
             fields = [field for field in fields if field['name'] != 'id']
 
@@ -493,7 +493,6 @@ class ExportFormat(object):
 
             response_data = self.from_group_data(fields, tree)
         else:
-            Model = Model.with_context(import_compat=import_compat)
             records = Model.browse(ids) if ids else Model.search(domain, offset=0, limit=False, order=False)
 
             export_data = records.export_data(field_names).get('datas', [])