[IMP] tools: keep additional data when sanitizing

Purpose is to allow to have ``data-behavior-props`` and ``data-prop-name``
on HTML nodes and keep it even when HTML content is sanitized. Those attributes
will be used notably in Knowledge application to store some structured content
e.g. used to populate props.

Prepares Task-2796156
Prepares odoo/enterprise#29423

X-original-commit: 7ddb4685567c115ca4e14fa7e5f845b0cb33fd7c
Part-of: odoo/odoo#101694

odoo/tools/mail.py

@@ -35,6 +35,7 @@ safe_attrs = clean.defs.safe_attrs | frozenset(
      'data-publish', 'data-id', 'data-res_id', 'data-interval', 'data-member_id', 'data-scroll-background-ratio', 'data-view-id',
      'data-class', 'data-mimetype', 'data-original-src', 'data-original-id', 'data-gl-filter', 'data-quality', 'data-resize-width',
      'data-shape', 'data-shape-colors', 'data-file-name', 'data-original-mimetype',
+     'data-behavior-props', 'data-prop-name',  # knowledge commands
      ])
 SANITIZE_TAGS = {
     # allow new semantic HTML5 tags