[FIX] website_form: verify that both input and textarea select form

When Jabberwock was introduced in [1], forms were not selected anymore
by clicking on the form fields.
That behavior got fixed when Jabberwock was removed in [2] but this
commit introducing a test about it was not attached to a task - and did
not get merged at the time.

Before this commit there was no test to verify if the form became
selected when clicking on one of its input field or textarea.

After this commit there is a test that makes sure that the form is
selected when the user clicks on either an input field or a textarea.
Also added the renaming of a field label followed by a blur to ensure
it triggers all UI events.

[1] https://github.com/odoo/odoo/commit/347f4413d1b1a2b1a6a9ecd6d9c20cf7f3ec5ff3
[2] https://github.com/odoo/odoo/commit/e5572c317a7775a58675ed73efc89b5c9f6c0c39



task-2729643

closes odoo/odoo#63256

Signed-off-by: Romain Derie (rde) <rde@odoo.com>