Test: Commands in watermark

[chrmarti]

Test for #12534

• Windows - @gregvanl
• Linux - @jrieken

Complexity: 2

• Check whether or not you are shown the watermark on the empty editor area (the part of the experiment you are in)
  • Verify it stays the same when restarting (optionally: updating)
• If shown, verify:
  • it displays correctly
  • shows the correct keybindings
  • updates when changing keybindings
• If not shown, verify:
  • the logo displays all centered (as before)
• Repeat with the hidden setting "telemetry.experiments.showCommandsWatermark" set to the opposite

[gregvanl]

Suggestions #12797 and #12800

[gregvanl]

Couldn't get the telemetry.experiments.showCommandsWatermark switch to work #12807