macOS: Make the behaviour of ComponentPeer::grabFocus match the other platforms

This partially reverts f43784dc: "macOS:  Propagate focus loss message when resigning key window status and only grab focus if window can become the key window"

modules/juce_gui_basics/native/juce_mac_NSViewComponentPeer.mm

@@ -1558,7 +1558,7 @@ public:
 
     void grabFocus() override
     {
-        if (window != nil && [window canBecomeKeyWindow])
+        if (window != nil)
         {
             [window makeKeyWindow];
             [window makeFirstResponder: view];

modules/juce_gui_basics/windows/juce_ComponentPeer.h

@@ -70,8 +70,7 @@ public:
                                                         performAnyPendingRepaintsNow() method is called. */
         windowIgnoresKeyPresses     = (1 << 10),   /**< Tells the window not to catch any keypresses. This can
                                                         be used for things like plugin windows, to stop them interfering
-                                                        with the host's shortcut keys. This will prevent the window from
-                                                        gaining keyboard focus. */
+                                                        with the host's shortcut keys. */
         windowIsSemiTransparent     = (1 << 30)    /**< Not intended for public use - makes a window transparent. */
 
     };