Userland: Port GUI::Application::show_tooltip() to String

This most importantly gets rid of a chain of "String to DeprecatedString
to String" transformations when setting a tooltip from GUI::Widget's
set_tooltip function.

Userland/Applications/Maps/MapWidget.cpp

@@ -187,7 +187,7 @@ void MapWidget::mousemove_event(GUI::MouseEvent& event)
             marker_image->height()
         };
         if (marker_rect.contains(event.x(), event.y())) {
-            GUI::Application::the()->show_tooltip(marker.tooltip.value().to_deprecated_string(), this);
+            GUI::Application::the()->show_tooltip(marker.tooltip.value(), this);
             return;
         }
     }

Userland/Applications/PixelPaint/Tools/GuideTool.cpp

@@ -74,7 +74,7 @@ void GuideTool::on_mousedown(Layer*, MouseEvent& event)
 
     if (m_selected_guide) {
         m_guide_origin = m_selected_guide->offset();
-        GUI::Application::the()->show_tooltip_immediately(DeprecatedString::formatted("{}", m_guide_origin), GUI::Application::the()->tooltip_source_widget());
+        GUI::Application::the()->show_tooltip_immediately(MUST(String::number(m_guide_origin)), GUI::Application::the()->tooltip_source_widget());
     }
 }
 
@@ -120,7 +120,7 @@ void GuideTool::on_mousemove(Layer*, MouseEvent& event)
 
     m_selected_guide->set_offset(new_offset);
 
-    GUI::Application::the()->show_tooltip_immediately(DeprecatedString::formatted("{}", new_offset), GUI::Application::the()->tooltip_source_widget());
+    GUI::Application::the()->show_tooltip_immediately(MUST(String::number(new_offset)), GUI::Application::the()->tooltip_source_widget());
 
     editor()->update();
 }

Userland/DevTools/Profiler/TimelineTrack.cpp

@@ -130,7 +130,7 @@ void TimelineTrack::mousemove_event(GUI::MouseEvent& event)
         Gfx::IntRect hoverable_rect { x - hoverable_padding, frame_thickness(), hoverable_padding * 2, height() - frame_thickness() * 2 };
         if (hoverable_rect.contains_horizontally(event.x())) {
             auto const& data = signpost.data.template get<Profile::Event::SignpostData>();
-            GUI::Application::the()->show_tooltip_immediately(DeprecatedString::formatted("{}, {}", data.string, data.arg), this);
+            GUI::Application::the()->show_tooltip_immediately(MUST(String::formatted("{}, {}", data.string, data.arg)), this);
             hovering_a_signpost = true;
             return IterationDecision::Break;
         }

Userland/Libraries/LibGUI/Application.cpp

@@ -25,9 +25,9 @@ class Application::TooltipWindow final : public Window {
     C_OBJECT(TooltipWindow);
 
 public:
-    void set_tooltip(DeprecatedString const& tooltip)
+    void set_tooltip(String tooltip)
     {
-        m_label->set_text(String::from_deprecated_string(tooltip).release_value_but_fixme_should_propagate_errors());
+        m_label->set_text(move(tooltip));
         int tooltip_width = m_label->effective_min_size().width().as_int() + 10;
         int line_count = m_label->text().count("\n"sv);
         int font_size = m_label->font().pixel_size_rounded_up();
@@ -152,7 +152,7 @@ Action* Application::action_for_shortcut(Shortcut const& shortcut) const
     return (*it).value;
 }
 
-void Application::show_tooltip(DeprecatedString tooltip, Widget const* tooltip_source_widget)
+void Application::show_tooltip(String tooltip, Widget const* tooltip_source_widget)
 {
     if (!Desktop::the().system_effects().tooltips())
         return;
@@ -173,7 +173,7 @@ void Application::show_tooltip(DeprecatedString tooltip, Widget const* tooltip_s
     }
 }
 
-void Application::show_tooltip_immediately(DeprecatedString tooltip, Widget const* tooltip_source_widget)
+void Application::show_tooltip_immediately(String tooltip, Widget const* tooltip_source_widget)
 {
     if (!Desktop::the().system_effects().tooltips())
         return;

Userland/Libraries/LibGUI/Application.h

@@ -41,8 +41,8 @@ public:
     void register_global_shortcut_action(Badge<Action>, Action&);
     void unregister_global_shortcut_action(Badge<Action>, Action&);
 
-    void show_tooltip(DeprecatedString, Widget const* tooltip_source_widget);
-    void show_tooltip_immediately(DeprecatedString, Widget const* tooltip_source_widget);
+    void show_tooltip(String, Widget const* tooltip_source_widget);
+    void show_tooltip_immediately(String, Widget const* tooltip_source_widget);
     void hide_tooltip();
     Widget const* tooltip_source_widget() { return m_tooltip_source_widget; }
 

Userland/Libraries/LibGUI/Widget.cpp

@@ -1122,7 +1122,7 @@ void Widget::set_tooltip(String tooltip)
 void Widget::show_or_hide_tooltip()
 {
     if (has_tooltip())
-        Application::the()->show_tooltip(m_tooltip.to_deprecated_string(), this);
+        Application::the()->show_tooltip(m_tooltip, this);
     else
         Application::the()->hide_tooltip();
 }

Userland/Libraries/LibWebView/OutOfProcessWebView.cpp

@@ -65,7 +65,7 @@ OutOfProcessWebView::OutOfProcessWebView()
     };
 
     on_enter_tooltip_area = [](auto, auto tooltip) {
-        GUI::Application::the()->show_tooltip(tooltip, nullptr);
+        GUI::Application::the()->show_tooltip(MUST(String::from_deprecated_string(tooltip)), nullptr);
     };
 
     on_leave_tooltip_area = []() {