Common/CommonFuncs: Remove now-unneccessary ArraySize function

Since C++17, non-member std::size() is present in the standard library
which also operates on regular C arrays. Given that, we can just replace
usages of ArraySize with that where applicable.

In many cases, we can just change the actual C array ArraySize() was
called on into a std::array and just use its .size() member function
instead.

In some other cases, we can collapse the loops they were used in, into a
ranged-for loop, eliminating the need for en explicit bounds query.

Source/UnitTests/Common/CommonFuncsTest.cpp

@@ -6,18 +6,6 @@
 
 #include "Common/CommonFuncs.h"
 
-TEST(CommonFuncs, ArraySizeFunction)
-{
-  char test[4];
-  u32 test2[42];
-
-  EXPECT_EQ(4u, ArraySize(test));
-  EXPECT_EQ(42u, ArraySize(test2));
-
-  (void)test;
-  (void)test2;
-}
-
 TEST(CommonFuncs, CrashMacro)
 {
   EXPECT_DEATH({ Crash(); }, "");