accounting: Always show "Group Analytics" on Trial Balance Dialog

This field was only displayed if any of these was enabled:

• by function analytics
• by project analytics
• by category analytics

and it allows requesting reports per function, project, categories and section.

The problem is that if any analytics was explicitly enabled, we never allow users to get a break down by section.

Always display the field, so that user can always select section.

This does not make much sense when there's only one section though.