This commit adds the ability to enable spellcheck on input/textarea only
if they are in focus. This avoids the UI to be bloated with unwanted
underlined text on unfocused elements. It is especially useful in a context
of form view in always edit mode.
A core hook has been introduced to allow other components to use the same
behavior without reimplementing it. It is currently used by the TextField.
It means it is also used in the HtmlField. Tests have been written, both for
the field component, and the core hook.
task #2861428
Part-of: odoo/odoo#106866
luvi
cc411a5076