Fix recursive attempts to open the log file in the GameLauncher (#1114)

* Fix recursive attempts to open the log file in the GameLauncher

The AzFramework Application has been updated to default the @user@ and
@log@ aliases to the <engine-root>/user and <engine-root>/user/log
folder respectively if a project isn't set.

Fixed the SystemFile class to support negative offsets if Seek() as per
standard seek function such as fseek

Updated the CrySystem CLog class to use SystemFile instead of FileIOBase
to avoid any asserts that would cause CLog::OpenFile to be recursively
called infinitely

* Removing unused Force Closed variable

* AZ::IO::SystemFile build fixes for Unix platforms. Added a copy constructor for LUAEditorContextInterface.h to fix the LuaEditor build

* Adding missing includes to the WindowsAPI and Android SystemFile headers

Code/CryEngine/CrySystem/SystemInit.cpp

@@ -1208,7 +1208,7 @@ bool CSystem::Init(const SSystemInitParams& startupParams)
         {
             assetPlatform = AzFramework::OSPlatformToDefaultAssetPlatform(AZ_TRAIT_OS_PLATFORM_CODENAME);
             AZ_Warning(AZ_TRACE_SYSTEM_WINDOW, false, R"(A valid asset platform is missing in "%s/assets" key in the SettingsRegistry.)""\n"
-                R"(This typically done by setting he "assets" field in the bootstrap.cfg for within a .setreg file)""\n"
+                R"(This typically done by setting the "assets" field within a .setreg file)""\n"
                 R"(A fallback of %s will be used.)",
                 AZ::SettingsRegistryMergeUtils::BootstrapSettingsRootKey,
                 assetPlatform.c_str());