Cleanup includes

Improved manually with the help of neovim LSP warnings and iwyu:

    iwyu -Ibuilddir/app/ -Iapp/src/ app/src/XXX.c

app/src/util/average.h

@@ -3,9 +3,6 @@
 
 #include "common.h"
 
-#include <stdbool.h>
-#include <stdint.h>
-
 struct sc_average {
     // Current average value
     float avg;