managers/helpers: add missing includes (#11969)

* managers: include string header

Fixes error `implicit instantiation of undefined template 'std::basic_string<char>'` on llvm/musl

* helpers: include unistd header

Fixes error `use of undeclared identifier 'pipe'` on llvm/musl

src/helpers/MainLoopExecutor.cpp

@@ -1,6 +1,7 @@
 #include "MainLoopExecutor.hpp"
 #include "../managers/eventLoop/EventLoopManager.hpp"
 #include "../macros.hpp"
+#include <unistd.h>
 
 static int onDataRead(int fd, uint32_t mask, void* data) {
     ((CMainLoopExecutor*)data)->onFired();

src/managers/animation/DesktopAnimationManager.hpp

@@ -2,6 +2,7 @@
 
 #include "../../helpers/memory/Memory.hpp"
 #include "../../desktop/DesktopTypes.hpp"
+#include <string>
 
 class CDesktopAnimationManager {
   public: