Use offsets for the carousel instead of a page view.

Fix carousel for RTL layouts.

RiotSwiftUI/Modules/Onboarding/SplashScreen/View/OnboardingSplashScreenPageIndicator.swift

@@ -18,11 +18,22 @@ import SwiftUI
 
 @available(iOS 14.0, *)
 struct OnboardingSplashScreenPageIndicator: View {
+    
     @Environment(\.theme) private var theme
     
     let pageCount: Int
     let pageIndex: Int
     
+    internal init(pageCount: Int, pageIndex: Int) {
+        self.pageCount = pageCount
+        
+        if pageIndex == -1 {
+            self.pageIndex = pageCount - 1
+        } else {
+            self.pageIndex = pageIndex % pageCount
+        }
+    }
+    
     var body: some View {
         HStack {
             ForEach(0..<pageCount) { index in