data not refreshed when model changes when using data-sorter

[ctcpip]

same cause of #17 -- but the fix for that was only applied to data-filterer. that same fix needs to be applied to data-sorter as well (and maybe other components)

basically when you have code like this:

      {{#data-sorter data=model as |ds|}}
        {{#data-table data=ds.data as |t|}}
          {{t.sortableColumn propertyName='name' name="Name"}}
        {{/data-table}}
      {{/data-sorter}}

if the model changes, the table does not show the new data

the fix is the same as for #17 (fixed by #18)

-  sortedData:computed('data', 'sortFields.[]', 'sorter', function() {
+  sortedData:computed('data.[]', 'sortFields.[]', 'sorter', function() {