Dropdown to select property for table-rows grouping

Also component allows to select sort order for property used for grouping

Usage example:

<ModelsTable
  @data={{data}}
  @columns={{columns}}
  @useDataGrouping={{true}}
  @currentGroupingPropertyName="firstName"
  @displayGroupedValueAs="column"
  @dataGroupProperties={{dataGroupProperties}} as |MT|>
  <MT.DataGroupBySelect />
  {{! ... }}
</ModelsTable>

Block usage example:

<ModelsTable
  @data={{data}}
  @columns={{columns}}
  @useDataGrouping={{true}}
  @currentGroupingPropertyName="firstName"
  @displayGroupedValueAs="column"
  @dataGroupProperties={{dataGroupProperties}} as |MT|>
  <MT.DataGroupBySelect as |DGBS|>
    <label>{{MT.themeInstance.groupByLabelMsg}}</label>
    <DGBS.Select />
    <button
      class={{MT.themeInstance.sortGroupedPropertyBtn}}
      onclick={{action DGBS.sort}}>
      <i class={{if
       (is-equal MT.sortByGroupedFieldDirection "asc")
       MT.themeInstance.sortAscIcon
       MT.themeInstance.sortDescIcon}}>
      </i>
    </button>
  </MT.DataGroupBySelect>
</ModelsTable>

References to the following actions are yielded:

• sort - do sort by property name used to group rows