internal: introduce new types to avoid unsigned int rollover and signed int overflow (#7216)

* framebuffer: avoid gluint overflow

GLuint was being initialized to -1 and rolling over to unsigned int max,
its defined behaviour but very unnecessery. add a bool and use it for
checking if allocated or not.

* opengl: avoid gluint rollover

-1 rolls over to unsigned int max, use 0xFF instead.

* core: big uint64_t to int type conversion

there were a few uint64_t to int implicit conversions overflowing int
and causing UB, make all monitor/workspaces/windows use the new
typedefs. also fix the various related 64 to 32 implicit conversions
going around found with -Wshorten-64-to-32

src/render/Framebuffer.hpp

@@ -18,7 +18,8 @@ class CFramebuffer {
     Vector2D     m_vSize;
 
     SP<CTexture> m_cTex;
-    GLuint       m_iFb = -1;
+    GLuint       m_iFb;
+    bool         m_iFbAllocated{false};
 
     SP<CTexture> m_pStencilTex;
 };