Before this commit, avatar url of author of message always had
style `.o_object_fit_cover`, which makes a nice crop when
ratio of image does not match ratio of the `img`.
When the author of message is a company, it shows the logo of the
company, and it doesn't look nice to crop it.
This commit fixes the issue by using `.o_object_fit_contain` for
avatar of company, so that the logo is fully visible.
When displaying the avatar of a partner whose `is_company` is
undefined, the data is group-fetched, in order for models to
eventually know the value of `is_company` and use the correct
desirable showing.
Task-3381748
closesodoo/odoo#133311
X-original-commit: 48194366f2364e2eb9d99dc4fb71e2de83d8f7a2
Signed-off-by: Alexandre Kühn (aku) <aku@odoo.com>