LibWeb: Use platform's OpenGL in WebGL when it is available

This change makes WebGL to use LibGL only in SerenityOS, and the
platform's OpenGL driver in Ladybird if it is available.

This is implemented by introducing wrapper class between WebGL and
OpenGL calls. This way it will also be possible to provide more
complete support in Ladybird even if we don't yet have all needed
calls implemented in LibGL.

For now, the wrapper class makes all GL calls virtual. However, we
can get rid of this and implement it at compile time in case of
performance problems.

Userland/Libraries/LibWeb/CMakeLists.txt

@@ -621,6 +621,7 @@ set(SOURCES
     WebDriver/Screenshot.cpp
     WebDriver/TimeoutsConfiguration.cpp
     WebGL/EventNames.cpp
+    WebGL/OpenGLContext.cpp
     WebGL/WebGLContextAttributes.cpp
     WebGL/WebGLContextEvent.cpp
     WebGL/WebGLRenderingContext.cpp
@@ -679,12 +680,18 @@ set(GENERATED_SOURCES
 serenity_lib(LibWeb web)
 
 # NOTE: We link with LibSoftGPU here instead of lazy loading it via dlopen() so that we do not have to unveil the library and pledge prot_exec.
-target_link_libraries(LibWeb PRIVATE LibCore LibCrypto LibJS LibMarkdown LibHTTP LibGemini LibGL LibGUI LibGfx LibIPC LibLocale LibRegex LibSoftGPU LibSyntax LibTextCodec LibUnicode LibAudio LibVideo LibWasm LibXML LibIDL)
+target_link_libraries(LibWeb PRIVATE LibCore LibCrypto LibJS LibMarkdown LibHTTP LibGemini LibGUI LibGfx LibIPC LibLocale LibRegex LibSoftGPU LibSyntax LibTextCodec LibUnicode LibAudio LibVideo LibWasm LibXML LibIDL)
 link_with_locale_data(LibWeb)
 
 if (HAS_ACCELERATED_GRAPHICS)
+    target_link_libraries(LibWeb PRIVATE ${ACCEL_GFX_LIBS})
     target_sources(LibWeb PRIVATE Painting/PaintingCommandExecutorGPU.cpp)
     target_link_libraries(LibWeb PRIVATE LibAccelGfx)
+    target_compile_definitions(LibWeb PRIVATE HAS_ACCELERATED_GRAPHICS)
+endif()
+
+if (SERENITYOS)
+    target_link_libraries(LibWeb PRIVATE LibGL)
 endif()
 
 generate_js_bindings(LibWeb)