Currently the "refresh" animations look quite different depending on the
page and the type of event (refresh button, initial page load, ...).
This tries to make a start by updating the "Fetching info ..." animation
(shown on initial page load) with Patternfly's "empty state" pattern [1]
in combination with an animated spinner.
For "Refreshable" pages, a similar animation is used in the upper right
corner (like before) but with an updated spinner and icon. By using a
dedicated React component rather than a base class, the "refresh" button
can be more nicely integrated into the layout of the page/container and
it doesn't look "out of scope" for the refreshable component.
For the API page I've removed the refresh completely since it wasn't
implemented at all.
[1] https://www.patternfly.org/v4/documentation/react/components/emptystate
Change-Id: I2274c212f14aece27ff49bfc7900d9b1a0fd01d0
ed9d0446d5