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.

Tools/Sources/Commands/BuildSDK.swift

@@ -47,7 +47,7 @@ struct BuildSDK: AsyncParsableCommand {
                 Run the following command to install them:
                 
                 rustup target add \(missingTargets.joined(separator: " "))
-
+                
                 """
             default:
                 return nil