ui: ceph: improve discoverability of warning details

ui: ceph: improve discoverability of warning details

by
* replacing the info button with expandable rows that contain the
  details of the warning
* adding two action buttons to copy the summary and details
* making the text selectable

The row expander works like the one in the mail gateway tracking center
-> doubleclick only opens it.

The height of the warning grid is limited to not grow too large.
A Diffstore is used to avoid expanded rows being collapsed on an update.

The rowexpander cannot hide the toggle out of the box. Therefore, if
there is no detailed message for a warning, we show a placeholder text.
We could consider extending it in the future to only show the toggle if
a defined condition is met.

Signed-off-by: Aaron Lauterer <a.lauterer@proxmox.com>
Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>