CActor: Make AddToRenderer() non-const

This member function alters instance state in a few implementations, so
it shouldn't be made const.

The state manager parameter also shouldn't be const. Retrieved data
from the post constructed instance is further modified in some
implementations. This removes the constness on this parameter in order
to fix more const_cast usages in a follow-up change.

Runtime/World/CWallCrawlerSwarm.cpp

@@ -983,7 +983,7 @@ void CWallCrawlerSwarm::RenderParticles() const {
   }
 }
 
-void CWallCrawlerSwarm::AddToRenderer(const zeus::CFrustum&, const CStateManager& mgr) const {
+void CWallCrawlerSwarm::AddToRenderer(const zeus::CFrustum&, CStateManager& mgr) {
   if (!GetActive()) {
     return;
   }