Add explicit sizing to sheets on macOS

Give player, download, source, and login sheets minimum frame dimensions on macOS so they open at a usable size instead of collapsing.

Yattee/Views/Video/VideoInfoView.swift

@@ -1984,6 +1984,9 @@ struct VideoInfoView: View {
                 }
                 #endif
             }
+            #if os(macOS)
+            .frame(minWidth: 500, minHeight: 550)
+            #endif
         }
     }