Paywalls: updated multi-package bold template design (#2908)

Added new border around unselected packages.
(Note that the test snapshots don't included blurred background)

![simulator_screenshot_BF1077DF-9976-4404-9AFB-9A45798CC619](https://github.com/RevenueCat/purchases-ios/assets/685609/f78245d3-ee8a-4afa-8674-12ab9698bd3f)

RevenueCatUI/Templates/MultiPackageBoldTemplate.swift

@@ -150,8 +150,16 @@ private struct MultiPackageTemplateContent: View {
         .multilineTextAlignment(.leading)
         .frame(maxWidth: .infinity, alignment: alignment)
         .foregroundColor(self.configuration.colors.foregroundColor)
+        .overlay {
+            if selected {
+                EmptyView()
+            } else {
+                RoundedRectangle(cornerRadius: Self.cornerRadius)
+                    .stroke(self.configuration.colors.foregroundColor, lineWidth: 2)
+            }
+        }
         .background {
-            RoundedRectangle(cornerRadius: 15, style: .continuous)
+            RoundedRectangle(cornerRadius: Self.cornerRadius, style: .continuous)
                 .foregroundColor(
                     selected
                     ? Self.selectedBackgroundColor
@@ -203,6 +211,7 @@ private struct MultiPackageTemplateContent: View {
     }
 
     private static let iconSize: CGFloat = 100
+    private static let cornerRadius: CGFloat = 15
 
     #if !os(macOS) && !os(watchOS)
     private static let selectedBackgroundColor: Color = .init(