Renderer: rewrite render scheduling (#8683)

This rewrites renderer scheduling. Occlusion is now unified in a new Pass type.

src/render/pass/PassElement.cpp

@@ -0,0 +1,17 @@
+#include "PassElement.hpp"
+
+std::optional<CBox> IPassElement::boundingBox() {
+    return std::nullopt;
+}
+
+CRegion IPassElement::opaqueRegion() {
+    return {};
+}
+
+bool IPassElement::disableSimplification() {
+    return false;
+}
+
+void IPassElement::discard() {
+    ;
+}