ES Querying API changes

[kadamidev]

Description of the Problem / Feature

• Refactored to simplify the API and make it more versatile
• Added support for better filtering capabilities; gt, gte, lt, lte, eq, neq and ES range/term/match/exists filters
• Adjusted relevance algo, reduced weighting of non article types
• Reduced weighting of non English works
• Refactored to fix single filtering on different entities besides works

Instructions on making this work

• Merging this will affect existing front end branches that were using the previous search API, effects are minor, but the frontend index-search-api branch should be merged into those to make sure pagination and sorting functionality work.