It seems fractional spacing results in different behavior across browsers,
including unbalanced spacing, making the avatar appear uncentered.
Here we avoid this by using integers that seem to closely match the comps.
Fixes https://github.com/vector-im/riot-web/issues/8134.
This returns to the previous behavior of avatar only without a button when the
custom status feature is disabled so that you don't get pointer cursor for
something that does nothing when clicked.
The avatar ring spacing is kept consistent with and without the feature enabled
by using a different class in CSS.
Adjusts the appearance of the avatar ring to match the latest comps.
In addition, we now always render the surrounding button element, which
simplifies styling since the same size is now occupied both with and without the
feature.
This improves alignment between text in the composer and text in the message
history (https://github.com/vector-im/riot-web/issues/8111).
