Fix or workaround recent extension API compatibility issues

- Add compatibility methods for `RenderingDevice::shader_create_from_bytecode`
  and `CodeEdit::get_text_for_symbol_loopup`.
- Silence errors which now have compatibility methods.
- Acknowledge GraphEdit/GraphNode compat breakage, intended and WIP.

servers/rendering/rendering_device.h

@@ -141,6 +141,11 @@ private:
 protected:
 	static void _bind_methods();
 
+#ifndef DISABLE_DEPRECATED
+	RID _shader_create_from_bytecode_bind_compat_79606(const Vector<uint8_t> &p_shader_binary);
+	static void _bind_compatibility_methods();
+#endif
+
 	Capabilities device_capabilities;
 
 public: