Add OptGroup support to WebformOption entity.

Problem

As more reusable options are added to the website the list of options is getting unmanageable.

Solution

Add OptGroup support to WebformOption entity.

Tasks

• Update WebformOptions schema
• Add group to export options
• Update WebformListBuilder, sort by group and title.
• Update list of reusable options
• Default uncategorize to 'Other' which should be last.

OptGroups

• Date/Time
• Geographic
• Demographic
• Likert
• Common