LibGUI: Set parent icon, margins and disable resize for InputBox

Gives a more compact, uniform appearance to input boxes.

Libraries/LibGUI/InputBox.cpp

@@ -49,6 +49,9 @@ InputBox::~InputBox()
 int InputBox::show(String& text_value, Window* parent_window, const StringView& prompt, const StringView& title)
 {
     auto box = InputBox::construct(parent_window, prompt, title);
+    box->set_resizable(false);
+    if (parent_window)
+        box->set_icon(parent_window->icon());
     auto result = box->exec();
     text_value = box->text_value();
     return result;
@@ -62,19 +65,23 @@ void InputBox::build()
     int title_width = widget.font().width(title()) + 24 /* icon, plus a little padding -- not perfect */;
     int max_width = AK::max(text_width, title_width);
 
-    set_rect(x(), y(), max_width + 80, 80);
+    set_rect(x(), y(), max_width + 140, 62);
 
     widget.set_layout<VerticalBoxLayout>();
     widget.set_fill_with_background_color(true);
 
-    widget.layout()->set_margins({ 8, 8, 8, 8 });
-    widget.layout()->set_spacing(8);
+    widget.layout()->set_margins({ 6, 6, 6, 6 });
+    widget.layout()->set_spacing(6);
 
-    auto& label = widget.add<Label>(m_prompt);
+    auto& label_editor_container = widget.add<Widget>();
+    label_editor_container.set_size_policy(SizePolicy::Fill, SizePolicy::Fill);
+    label_editor_container.set_layout<HorizontalBoxLayout>();
+
+    auto& label = label_editor_container.add<Label>(m_prompt);
     label.set_size_policy(SizePolicy::Fixed, SizePolicy::Fixed);
     label.set_preferred_size(text_width, 16);
 
-    m_text_editor = widget.add<TextBox>();
+    m_text_editor = label_editor_container.add<TextBox>();
     m_text_editor->set_size_policy(SizePolicy::Fill, SizePolicy::Fixed);
     m_text_editor->set_preferred_size(0, 19);
 
@@ -85,7 +92,9 @@ void InputBox::build()
 
     auto& button_container_inner = button_container_outer.add<Widget>();
     button_container_inner.set_layout<HorizontalBoxLayout>();
-    button_container_inner.layout()->set_spacing(8);
+    button_container_inner.layout()->set_spacing(6);
+    button_container_inner.layout()->set_margins({ 4, 4, 0, 4 });
+    button_container_inner.layout()->add_spacer();
 
     m_ok_button = button_container_inner.add<Button>();
     m_ok_button->set_size_policy(SizePolicy::Fill, SizePolicy::Fixed);