- In DataForSeoMerchantAmazonProductsProcessor deleted incorrect recursion for nested_items
- Added DataForSeoLabsGoogleKeywordResearchProcessor class
- Updated table to have multiple secondary_keyword_intents_probability_ columns
- Updated monthly_searches columns from integer to text
- Updated SERP results count and search volume columns to unsignedBigInteger
- Modified summarize_params() to add $detectTaskArrays argument
  (since DataForSEO wraps $params in an array of tasks)