Aggregation types can disable column sorting, e.g. both the current
group concatenation types. If such a type is selected for a column
we should update the report sorting options, ensuring that only those
columns that can be sorted are available for selection.
Implement UI elements for editing columns of a report, taking their
definitions from the selected datasource.
Co-authored-By: David Matamoros <davidmc@moodle.com>
Co-authored-By: Mikel Martín <mikel@moodle.com>