[XB] Custom Forum Headers & Node Images 1.1.0

• Added optional forum list images with icon, thumbnail, and node background display modes.
• Added style properties for image sizes and background appearance.
• Extended list images to categories, pages, link forums, and search forums, including images in top-level category headings.
• Added custom search forum headers and a shared header and image editor for all supported node types.

• Added XF image optimization support.
• Added support for relative image paths.
• Added optional header image links with a choice of opening in the same tab or a new tab.

Added option to hide "select different" forum button

Added the ability to set a direct link to an image instead of uploading a file
Added image previews to the node list in the admin panel