Renderer: rewrite render scheduling (#8683)

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

src/render/pass/ClearPassElement.hpp

@@ -0,0 +1,25 @@
+#pragma once
+#include "PassElement.hpp"
+
+class CClearPassElement : public IPassElement {
+  public:
+    struct SClearData {
+        CHyprColor color;
+    };
+
+    CClearPassElement(const SClearData& data);
+    virtual ~CClearPassElement() = default;
+
+    virtual void                draw(const CRegion& damage);
+    virtual bool                needsLiveBlur();
+    virtual bool                needsPrecomputeBlur();
+    virtual std::optional<CBox> boundingBox();
+    virtual CRegion             opaqueRegion();
+
+    virtual const char*         passName() {
+        return "CClearPassElement";
+    }
+
+  private:
+    SClearData data;
+};