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/macros.hpp

@@ -27,6 +27,8 @@
 #define WORKSPACE_INVALID     -1L
 #define WORKSPACE_NOT_CHANGED -101
 
+#define MONITOR_INVALID -1L
+
 #define LISTENER(name)                                                                                                                                                             \
     void               listener_##name(wl_listener*, void*);                                                                                                                       \
     inline wl_listener listen_##name = {.notify = listener_##name}