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/input/TextInput.hpp

@@ -15,7 +15,7 @@ class CInputMethodV2;
 
 class CTextInput {
   public:
-    CTextInput(std::weak_ptr<CTextInputV3> ti);
+    CTextInput(WP<CTextInputV3> ti);
     CTextInput(STextInputV1* ti);
     ~CTextInput();
 
@@ -37,13 +37,13 @@ class CTextInput {
     wlr_surface* focusedSurface();
 
   private:
-    void                        setFocusedSurface(wlr_surface* pSurface);
-    void                        initCallbacks();
+    void             setFocusedSurface(wlr_surface* pSurface);
+    void             initCallbacks();
 
-    wlr_surface*                pFocusedSurface = nullptr;
-    int                         enterLocks      = 0;
-    std::weak_ptr<CTextInputV3> pV3Input;
-    STextInputV1*               pV1Input = nullptr;
+    wlr_surface*     pFocusedSurface = nullptr;
+    int              enterLocks      = 0;
+    WP<CTextInputV3> pV3Input;
+    STextInputV1*    pV1Input = nullptr;
 
     DYNLISTENER(textInputEnable);
     DYNLISTENER(textInputDisable);