Adding support for SuperTable field

[xavianaxw]

With the current state of the plugin, there was no way to get a matchedValue when working within a SuperTable field even though the plugin managed to determine that the searched keyword exists in the field.

Looking at the source code.

expanded-search/src/services/ExpandedSearchService.php

Lines 206 to 209 in 60a2f9b

	elseif (is_object($fieldContents) && $fieldContents instanceof \verbb\supertable\elements\db\SuperTableBlockQuery)
	{
	//TODO: fix this somehow
	}

it seems that it has been omitted. I did some tinkering within my vendor/ and came up with this.

elseif (is_object($fieldContents) && $fieldContents instanceof \verbb\supertable\elements\db\SuperTableBlockQuery){
  $relatedValues = [];
  $matchedValue = '';
  foreach ($fieldContents->all() as $stBlock) {
    $stMatches = $this->findMatchesInFieldSet($stBlock, $term, $length);
    if (!is_null($stMatches)) {
      $matchedValue = $stMatches[1];
    }
  }
  return [$fieldHandle, $matchedValue, $relatedValues];
}

which is the exact replica to the MatrixBlockQuery if statement. I'm not really sure how to set this up myself to work with composer so was hoping if this could get updated with the plugin.