App polish part 5 (#1149)

- Set launch/splash screens to default background colour.
- Replace launch screen storyboard with info plist keys.
- Remove useless layout components in bubble styler.
- Fix lint error.
- Rename all assets.
- Update design of Analytics Prompt.

ElementX/Sources/Screens/Other/SplashScreenCoordinator.swift

@@ -27,10 +27,7 @@ class SplashScreenCoordinator: CoordinatorProtocol {
 /// these 2 screens are matched.
 struct SplashScreen: View {
     var body: some View {
-        Image(asset: Asset.Images.launchLogo)
-            .accessibilityHidden(true)
-            .frame(maxWidth: .infinity, maxHeight: .infinity)
-            .background { OnboardingBackgroundImage() }
+        Color.compound.bgCanvasDefault.ignoresSafeArea()
     }
 }