[IMP] web,*: enable owl list & form views

The new list and form views were merged recently [1], but they
weren't activated because they weren't 100% ready yet. This is now
the case. This commit adds those views to the view registry. As a
consequence, a lot of qunit tests and tours needed to be adapted,
mostly for selector changes.

We also add legacy list and form views to the view registry, with
keys 'legacy_list' and 'legacy_form'. This allows to force those
legacy views when necessary. For instance, we did it in views
using complex custom legacy x2many field widgets that haven't been
converted yet (we have a compatibility layer but it isn't complete
and doesn't support every advanced usecases).

[1] odoo/odoo#92475

Part-of: odoo/odoo#78221
Co-authored-by: Aaron Bohy <aab@odoo.com>
Co-authored-by: Bruno Boi <boi@odoo.com>
Co-authored-by: Géry Debongnie <ged@odoo.com>
Co-authored-by: Samuel Degueldre <sad@odoo.com>
Co-authored-by: Mathieu Duckerts-Antoine <dam@odoo.com>
Co-authored-by: Simon Genin (ges) <ges@odoo.com>
Co-authored-by: Francois (fge) <fge@odoo.com>
Co-authored-by: Michael Mattiello (mcm) <mcm@odoo.com>
Co-authored-by: Julien Mougenot <jum@odoo.com>
Co-authored-by: Lucas Perais (lpe) <lpe@odoo.com>
Co-authored-by: Jorge Pinna Puissant <jpp@odoo.com>
Co-authored-by: luvi <luvi@odoo.com>