Added new properties in the logstash pipeline: contentTags and contentTagsAggregation

In the logstash pipeline config, I've added 2 new properties, e.g.: configTags => ["description", "viewport"] configTagsAggregation => false .... This means that the HTML filter will extract the contents found in either of the HTML tags given: "description" or "viewport". If configTagsAggregation was true, the contents from each tag gets concatenated.

Note that if this property is present: extractBodyCss => ["listing__description", "section-container", ".ecl-page-header__body"] .... it takes precedence; thus, the filter first explores these CSS tags and only after them it explores configTags