Global filter element used within models-table.

Its value is used for all data-items and for each columns propertyName.

Usage example:

<ModelsTable @data={{data}} @columns={{columns}} as |MT|>
  <MT.GlobalFilter />
  {{! .... }}
</ModelsTable>

Block usage example:

<ModelsTable @data={{data}} @columns={{columns}} as |MT|>
  <MT.GlobalFilter>
    {{input value=MT.globalFilter}}
    <button disabled={{if MT.globalFilterUsed "disabled"}} {{action (mut MT.globalFilter) ""}}>
      Clear Global Filter
    </button>
  </MT.GlobalFilter>
  {{! .... }}
</ModelsTable>