explicity set background color of visualization container as the property of the parent container gets lost as soon as we enter fullscreen mode

Resolve "Show simulator status in simulator table"

Closes #172

See merge request acs/public/villas/VILLASweb!38

Merge branch '170-add-new-parameters-property-to-simulation-and-simulationmodel-which-gets-send-with-start-actions-to-villascontroller' into 'develop'

Resolve "Add new "parameters" property to Simulation and SimulationModel which gets send with start actions to VILLAScontroller"

Closes #170

See merge request acs/public/villas/VILLASweb!37