An accessibility scan (axe-core, WCAG 2 A/AA) of every page found 87
elements without a name. Icon-only buttons and links (the navbar's
administration menu on every page, the add/create buttons, the flavor
delete and back buttons) get a title, which is also their tooltip; the
labels of the language, architecture, chipset and filter selects point
at them; the memory bar is named. The shared delete confirmation page
had an empty <title> and heading, as no view passes "title": it says
"Delete <object>". The power-off form's aria-label was misspelled.
The CPU bar showed the average since the host booted, read for every
compute on every load of the VM list. The dialog now reads each compute's
graph endpoint (load over one second) when it opens, two computes at a
time so the reads hold at most two workers, and ignores answers of an
earlier opening. A host that cannot be read shows a dash. The since-boot
reading had no other caller and is removed.
