Further fixes to get the correct counter for the related courses carousel

eg
for 10 items we now have 10/4 = 2.5. Add on 0.5 = 3 panels
for 9 items we now have 9/4 = 2.25. Add on 0.5 = 2.75. Rounded to 3 panels.
for 8 items we now have 8/4 = 2. Add on 0.5 = 2.5 but then rounded back down to 2 panels