When there's no <map-properties>, pressing enter on a feature does not handle its link, when it has a map-a

[AliyanH]

Try with the following map to see the issue:

<mapml-viewer id="map3" style="width: 500px;height: 500px;" projection="CBMTILE" zoom="2" lat="45.5052040" lon="-75.2202344" controls controlslist="geolocation">
  <layer- label="Linked feature" checked>
    <map-meta name="projection" content="CBMTILE"></map-meta>   
      <map-feature id="linkedfeature">
        <map-featurecaption>Test link</map-featurecaption>
          <map-geometry cs="gcrs">
            <map-a href="#6,-75.705278,45.39777833216">           
              <map-point>
                <map-coordinates>-75.705278 45.397778</map-coordinates>
              </map-point>
            </map-a>
          </map-geometry>
      </map-feature>
  </layer->
</mapml-viewer>

• update the featureIndexOverlay.test test to use enter instead of click once this issue is fixed
• may be related to #875, would be good to resolve these together

[yhy0217]

Resolved in #891