[themes] /preferences, reliablity: warning icons & error logs link

When there is at least one errors or one failed checker test:
* the warning icon is displayed in the reliability column
* the link "View error logs and submit a bug report" is displayed on engine name tooltip.

Before:
* the warning icon was displayed only when one or more checker test(s) failed.
* the link "View error logs and submit a bug report" was not shown when a checker test failed but there were no error.