Add background image option for Browser

# Feature Request

## Motivation Behind Feature
It is very hard to make textured splash screen responsive, this will help solve the splash screen with textured backgrounds.

## Feature Description
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This should activate properties to the parent div
`background-image: ;`
`background-repeat: ;`

## Alternatives or Workarounds
Adding an image big enough so that no white spaces are displayed

No files or tests are named. Begin by tracing how the SplashScreenBackgroundImage and SplashScreenBackgroundRepeat preferences reach the splash-screen parent div. Done means both preferences apply the requested background-image and background-repeat behavior so textured splash screens can remain responsive without the stated workaround.

Written by the indexing model from the issue text.