Updated Series Icon - generate a larger icon

As per title, I've updated the Series Icon function to generate a larger icon during the icon upload process. Its currently based on the MEDIUM Avatar size (96x96) which is what the XFRM uses. I've updated the icon service to generate the Series Icon based on the LARGE Avatar Size (192x192), which is more inline with the List View Layout cover image size.

Note: This will NOT magically resize any existing Series Icons. You will need to edit the series icon for each series and upload a new image to generate a larger icon (suggested min size has increased from 100x100 to 200x200).