Update HeroImage to match the BigIcon component from Compound. (#3439)

We can move it across in a following PR.

ElementX/Sources/Screens/Authentication/LoginScreen/View/LoginScreen.swift

@@ -45,7 +45,7 @@ struct LoginScreen: View {
     /// The header containing the title and icon.
     var header: some View {
         VStack(spacing: 8) {
-            HeroImage(icon: \.lockSolid)
+            BigIcon(icon: \.lockSolid)
                 .padding(.bottom, 8)
             
             Text(L10n.screenLoginTitleWithHomeserver(context.viewState.homeserver.address))

ElementX/Sources/Screens/Authentication/ServerConfirmationScreen/View/ServerConfirmationScreen.swift

@@ -29,7 +29,7 @@ struct ServerConfirmationScreen: View {
     var header: some View {
         VStack(spacing: 8) {
             Image(systemSymbol: .personCropCircleFill)
-                .heroImage()
+                .bigIcon()
                 .padding(.bottom, 8)
             
             Text(context.viewState.title)

ElementX/Sources/Screens/Authentication/ServerSelectionScreen/View/ServerSelectionScreen.swift

@@ -32,7 +32,7 @@ struct ServerSelectionScreen: View {
     var header: some View {
         VStack(spacing: 8) {
             Image(asset: Asset.Images.serverSelectionIcon)
-                .heroImage(insets: 19)
+                .bigIcon(insets: 19)
                 .padding(.bottom, 8)
             
             Text(L10n.screenChangeServerTitle)