Some random tweaks made on a train 🚆 (#4636)

* Fix the search text field's tint colour.

* Don't allow optional content IDs in the placeholder avatar.

* Use SwiftUI to resolve the hex values in the Inspector app.

This fixes incorrect values being shown in dark/high-contrast modes.

* Fix a layout bug with the colour swatch in the Inspector app on iPhone.

* Switch to the chats tab when selecting a room with the global search screen.

* Run the latest SwiftFormat.

ElementX/Sources/Other/SwiftUI/Views/RoomAvatarImage.swift

@@ -69,7 +69,7 @@ struct RoomAvatarImage: View {
             // We will expand upon this with more stack sizes in the future.
             if users.count == 0 {
                 let _ = assertionFailure("We should never pass empty heroes here.")
-                PlaceholderAvatarImage(name: nil, contentID: nil)
+                PlaceholderAvatarImage(name: nil, contentID: "")
             } else if users.count == 2 {
                 let clusterSize = avatarSize.value * 1.6
                 ZStack {