Changes in index definitions, to significantly speedup...

Changes in index definitions, to significantly speedup 'condenser_api.get_trending_tags' call. Dedicated index created: hive_posts_category_id_payout_plus_pending_payout_depth_idx
Other indexes (mostly used by bridge_api.get_ranked_posts) has been extended by WHERE condition to eliminate rows does not matching conditions. This way indexes size has been significantly reduced.