css breaks in CiviReport for custom fields if fields are not defined for the parent table

This is a problem with the reports depending on the $columns['fields'] for definition information. So, if $columns['civicrm_membership']['fields'] is not defined but membership custom filters are specified the $colGroups that is assigned to the template (& which determines whether the accordian should be closed) is incorrect. This means the accordians don't have the right divs and as a result things like the date selector don't prefill correctly and criteria are dropped when exporting.

Further the $filters custom fields table array assigned to the template uses the 'grouping' section as it's key rather than the table names. This is not always assigned & is another cause for the described problem.

Fix is to ensure grouping is always defined for every table