[16.0][FIX] mail_activity_done: handle SQL queries without .replace()

[SupportSNDC]

Description

Fix AttributeError: 'SQL' object has no attribute 'replace' when using
mail_activity_done on Odoo 16.0 and accessing views with activity
progress bars (e.g. project task Kanban with activities).

Root cause

In Odoo 16.0, SQL queries are psycopg.sql.SQL / Composed objects
instead of plain strings, so calling .replace() on them fails.

Technical details

In mail_activity_done/models/mail_activity.py:

• In _read_progress_bar(), override execute() to:

  • convert the SQL object to a string via as_string(self._cr._cnx)
    when available, or fallback to str(query),
  • only perform replace() on the string when the expected pattern
    (WHERE res_model = ...) is present,
  • otherwise, call the original execute() with the unmodified query.

• Apply the same pattern in _search_activity_state() for its own
  SQL pattern, avoiding .replace() on the raw SQL object.

This preserves behaviour on earlier versions while making the module
compatible with Odoo 16.0.

Related issue

Fixes #1747