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/managers/eventLoop/EventLoopTimer.cpp

@@ -2,10 +2,8 @@
 #include <limits>
 #include "EventLoopManager.hpp"
 
-CEventLoopTimer::CEventLoopTimer(std::optional<std::chrono::system_clock::duration> timeout, std::function<void(std::shared_ptr<CEventLoopTimer> self, void* data)> cb_,
-                                 void* data_) :
-    cb(cb_),
-    data(data_) {
+CEventLoopTimer::CEventLoopTimer(std::optional<std::chrono::system_clock::duration> timeout, std::function<void(SP<CEventLoopTimer> self, void* data)> cb_, void* data_) :
+    cb(cb_), data(data_) {
 
     if (!timeout.has_value())
         expires.reset();
@@ -40,7 +38,7 @@ bool CEventLoopTimer::cancelled() {
     return wasCancelled;
 }
 
-void CEventLoopTimer::call(std::shared_ptr<CEventLoopTimer> self) {
+void CEventLoopTimer::call(SP<CEventLoopTimer> self) {
     expires.reset();
     cb(self, data);
 }