ksys/act: Add BaseProcHeapMgr

Why does this exist?

src/KingSystem/ActorSystem/actBaseProcHeapMgr.cpp

@@ -0,0 +1,19 @@
+#include "KingSystem/ActorSystem/actBaseProcHeapMgr.h"
+
+namespace ksys::act {
+
+SEAD_SINGLETON_DISPOSER_IMPL(BaseProcHeapMgr)
+
+BaseProcHeapMgr::BaseProcHeapMgr() = default;
+
+BaseProcHeapMgr::~BaseProcHeapMgr() = default;
+
+sead::Heap* BaseProcHeapMgr::getHeap() const {
+    return mHeap;
+}
+
+void BaseProcHeapMgr::setHeap(sead::Heap* heap) {
+    mHeap = heap;
+}
+
+}  // namespace ksys::act