macos: allow submitting clipboard confirmation with return

Before this change I couldn't submit the dialog with return. Or
cmd+return.

From what I understand the problem was that the `TextEditor` always
steals the default focus. I tried a bunch of workarounds I found to set
the default focus on the button, but none of them worked.

Then I thought: do we even need a full-on Text*Editor*? So I switched
`TextEditor` to `Text` with a `ScrollView`: things look the same, text
is selectable and scrollable, but I can hit return to submit the dialog.

macos/Sources/Features/ClipboardConfirmation/ClipboardConfirmationView.swift

@@ -48,10 +48,12 @@ struct ClipboardConfirmationView: View {
                     .padding()
             }
 
-            TextEditor(text: .constant(contents))
+            ScrollView {
+                Text(contents)
                     .textSelection(.enabled)
                     .font(.system(.body, design: .monospaced))
                     .padding(.all, 4)
+            }
 
             HStack {
                 Spacer()