test: Work around selenium Edge driver bug
test: Work around selenium Edge driver bug

Commit 9113eb5f60 triggered the old Edge selenium driver bug again where
elements that are scrolled off-page too far are not "visible" to
Selenium any more. Instead, look at units which starts much earlier in
the alphabet -- cockpit.socket, basic.target, and abrtd are on the top
of the page.

martinpitt/cockpit,mvollmer/cockpit,garrett/cockpit,martinpitt/cockpit,cockpit-project/cockpit,martinpitt/cockpit,mvollmer/cockpit,cockpit-project/cockpit,garrett/cockpit,cockpit-project/cockpit,mvollmer/cockpit,garrett/cockpit,martinpitt/cockpit,mvollmer/cockpit,garrett/cockpit,martinpitt/cockpit,cockpit-project/cockpit,cockpit-project/cockpit,mvollmer/cockpit,garrett/cockpit