* add: validation for analytics rules
* fix: tests for the same
* add: check for log_to_store and mandatory collection in rule for log type
* fix: missing of events
* fix: status codes in event manager
* fix: validation condition and tests for the same
* remove source collections for counter events rule
* support popular_queries by events API
* make search events API optional
* only keep doc_id param as mandatory for non search events
* add more validation tests
* remove live_query param for search events
* remove expanded_query param
* fix endpoints and unused vars
* add response on failure of writing events to db
* update response code
* handle userid with '_' & dont process events with log_to_store disabled
* use '%' as separator instead of '_'
* optimize '%' removal from userid
* remove analytics logging to tsv file
* add event_type in db_key & add tests for db persistence
* add test for sparsely added event retrieval
* update flag name to log events to store
* initial commit for analytics db with ttl
* refactor store class
* get last N events from db and minor changes
* add more tests & limit keys fetching per user
* add tests for persisting events
* fix test by adding unique event name
* fix persistance with analytics events
* early return raft_server check
* increment populairty count instead of overwrite
* extract method serialize_as_docs
* move func definition from header to source
* counter events refactor and tests
* fix test
* configure log_to_file per counter event
* add tests for persisting events
* fix test by adding unique event name
* fix persistance with analytics events
* early return raft_server check
* increment populairty count instead of overwrite
* extract method serialize_as_docs
* move func definition from header to source
