adjust test scenarios for bootchart

now tests

• first login cold (i.e. after reboot)
• second login cold
• third login warm

for the purposes of the first login a bunch of standard dirs are ripped
out of the user, since the user was alrady adjusted for testing scenarios
so it has a fixed wallpaper etc.

there's now also a sleep after finding sddm to ensure the system has
quieted down a bit and doesn't use resources which would go to the login
otherwise