Added a toggle fullscreen button (default F11) (#20272)

* Added a toggle fullscreen button (default F11)

* Removed un-needed comments

* Review Requested Changes

* Fixed Acidental Spacing Change

* bwoink, removed extraneous code

* nothing, litterally

Content.Client/Entry/EntryPoint.cs

@@ -3,6 +3,7 @@ using Content.Client.Changelog;
 using Content.Client.Chat.Managers;
 using Content.Client.Eui;
 using Content.Client.Flash;
+using Content.Client.Fullscreen;
 using Content.Client.GhostKick;
 using Content.Client.Guidebook;
 using Content.Client.Info;
@@ -49,6 +50,7 @@ namespace Content.Client.Entry
         [Dependency] private readonly IConfigurationManager _configManager = default!;
         [Dependency] private readonly IStylesheetManager _stylesheetManager = default!;
         [Dependency] private readonly IScreenshotHook _screenshotHook = default!;
+        [Dependency] private readonly FullscreenHook _fullscreenHook = default!;
         [Dependency] private readonly ChangelogManager _changelogManager = default!;
         [Dependency] private readonly RulesManager _rulesManager = default!;
         [Dependency] private readonly ViewportManager _viewportManager = default!;
@@ -123,6 +125,7 @@ namespace Content.Client.Entry
             _componentFactory.GenerateNetIds();
             _adminManager.Initialize();
             _screenshotHook.Initialize();
+            _fullscreenHook.Initialize();
             _changelogManager.Initialize();
             _rulesManager.Initialize();
             _viewportManager.Initialize();