2020-10-12 - Search Result add hooks

Service - Search Result Main has some tasks which must be performed by Service - Search Result (handlers), for example DigData, these are hardcoded into the Search Result Main code.

Some searchTypes will have optional tasks at points within the flow, for example variantProduct will have an extra step after the child product searchType has completed, but before processing DigData for each of the variant data saved into SearchResultData table.