Put a stretch menu background checkbox into the launcher (#5672)

CHANGELOG.md

@@ -83,6 +83,7 @@
     Feature #5610: Actors movement should be smoother
     Feature #5642: Ability to attach arrows to actor skeleton instead of bow mesh
     Feature #5649: Skyrim SE compressed BSA format support
+    Feature #5672: Make stretch menu background configuration more accessible
     Task #5480: Drop Qt4 support
     Task #5520: Improve cell name autocompleter implementation
 

apps/launcher/advancedpage.cpp

@@ -152,6 +152,7 @@ bool Launcher::AdvancedPage::loadSettings()
         // Match the index with the option (only 0, 1, 2, or 3 are valid). Will default to 0 if invalid.
         if (showOwnedIndex >= 0 && showOwnedIndex <= 3)
             showOwnedComboBox->setCurrentIndex(showOwnedIndex);
+        loadSettingBool(stretchBackgroundCheckBox, "stretch menu background", "GUI");
     }
 
     // Bug fixes
@@ -277,6 +278,7 @@ void Launcher::AdvancedPage::saveSettings()
         int showOwnedCurrentIndex = showOwnedComboBox->currentIndex();
         if (showOwnedCurrentIndex != mEngineSettings.getInt("show owned", "Game"))
             mEngineSettings.setInt("show owned", "Game", showOwnedCurrentIndex);
+        saveSettingBool(stretchBackgroundCheckBox, "stretch menu background", "GUI");
     }
 
     // Bug fixes

docs/source/reference/modding/settings/GUI.rst

@@ -72,7 +72,7 @@ The Bethesda provided assets have a 4:3 aspect ratio, but other assets are permi
 If this setting is false, the assets will be centered in their correct aspect ratio,
 with black bars filling the remainder of the screen.
 
-This setting can only be configured by editing the settings configuration file.
+This setting can be configured in the Interface section of Advanced tab of the launcher.
 
 subtitles
 ---------

files/ui/advancedpage.ui

@@ -714,6 +714,16 @@ True: In non-combat mode camera is positioned behind the character's shoulder. C
          </property>
         </widget>
        </item>
+       <item>
+        <widget class="QCheckBox" name="stretchBackgroundCheckBox">
+         <property name="toolTip">
+          <string>&lt;html&gt;&lt;head/&gt;&lt;body&gt;&lt;p&gt;Stretch menus, load screens, etc. to the window aspect ratio.&lt;/p&gt;&lt;/body&gt;&lt;/html&gt;</string>
+         </property>
+         <property name="text">
+          <string>Stretch menu background</string>
+         </property>
+        </widget>
+       </item>
        <item>
         <spacer name="verticalSpacer_2">
          <property name="orientation">