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/managers/eventLoop/EventLoopManager.cpp

@@ -76,8 +76,8 @@ void CEventLoopManager::removeTimer(SP<CEventLoopTimer> timer) {
 }
 
 static void timespecAddNs(timespec* pTimespec, int64_t delta) {
-    int delta_ns_low = delta % TIMESPEC_NSEC_PER_SEC;
-    int delta_s_high = delta / TIMESPEC_NSEC_PER_SEC;
+    auto delta_ns_low = delta % TIMESPEC_NSEC_PER_SEC;
+    auto delta_s_high = delta / TIMESPEC_NSEC_PER_SEC;
 
     pTimespec->tv_sec += delta_s_high;