internal: new shared_ptr and weak_ptr implementation (#5883)

moves std::shared_ptrs to a new implementation

Advantages:
- you can dereference a weak_ptr directly. This will obviously segfault on a nullptr deref if it's expired.
   - this is useful to avoid the .lock() hell where we are 100% sure the pointer _should_ be valid. (and if it isn't, it should throw.)
- weak_ptrs are still valid while the SP is being destroyed.
   - reasoning: while an object (e.g. CWindow) is being destroyed, its `weak_ptr self` should be accessible (the sp is still alive, and so is CWindow), but it's not because by stl it's already expired (to prevent resurrection)
   - this impl solves it differently. w_p is expired, but can still be dereferenced and used. Creating `s_p`s is not possible anymore, though.
   - this is useful in destructors and callbacks.

src/desktop/Window.cpp

@@ -8,7 +8,7 @@
 #include "../managers/TokenManager.hpp"
 
 PHLWINDOW CWindow::create() {
-    PHLWINDOW pWindow = std::shared_ptr<CWindow>(new CWindow);
+    PHLWINDOW pWindow = SP<CWindow>(new CWindow);
 
     pWindow->m_pSelf = pWindow;
 
@@ -894,7 +894,7 @@ PHLWINDOW CWindow::getGroupHead() {
 
 PHLWINDOW CWindow::getGroupTail() {
     PHLWINDOW curr = m_pSelf.lock();
-    while (!curr->m_sGroupData.pNextWindow.lock()->m_sGroupData.head)
+    while (!curr->m_sGroupData.pNextWindow->m_sGroupData.head)
         curr = curr->m_sGroupData.pNextWindow.lock();
     return curr;
 }