[CHG] *: make binary fields default to attachment=True

Check that it makes custom binary fields into attachment as that's the
main reason for the change: when users create binary fields via Studio,
they're necessarily db-stored (as the interface doesn't allow altering
the attachment attribute and it's unclear how we'd handle users
switching it on/off every time), which significantly bloats their
database (and burns storage & backup space), especially as the primary
use case for binary fields is adding images and documents to records.

* check that binary fields are properly created as attachment=True
* add attachment=False on fields where that seems relevant (most but not
  all of the fields previously using the default)
* remove occurrences of attachment=True

closes odoo/odoo#29308

addons/base_import_module/models/base_import_module.py

@@ -9,7 +9,7 @@ class BaseImportModule(models.TransientModel):
     _name = "base.import.module"
     _description = "Import Module"
 
-    module_file = fields.Binary(string='Module .ZIP file', required=True)
+    module_file = fields.Binary(string='Module .ZIP file', required=True, attachment=False)
     state = fields.Selection([('init', 'init'), ('done', 'done')], string='Status', readonly=True, default='init')
     import_message = fields.Char()
     force = fields.Boolean(string='Force init', help="Force init mode even if installed. (will update `noupdate='1'` records)")