* feat(backend): moved sql requests related to sessions table to one place
* feat(backend): refactoring in db.Saver handler
* feat(backend): hude refactoring in db/postgres module
* fix(backend): workable feature flags
* fix(backend): workable integrations
* fix(backend): workable sessions and projects modules
* fix(backend): added missed projects module to sessions
* feat(backend): renaming
* feat(backend): moved session struct to sessions module and split methods into interface, cache and storage levels
* feat(backend): moved project struct to projects module
* feat(backend): added projects model
* feat(backend): implemented new in memory cache for sessions and projects
* feat(backend): implemented new cache in projects
* feat(backend): there are 2 methods in cache module now: Get() and GetAndRefresh()
* feat(backend): added cache update operations
* fix(backend): fixed import cycle
* fix(backend): fixed panic in db message handler
* fix(backend): fixed panic in projects module
* fix(backend): fixed panic in sessions.GetDuration
* feat(backend): added direct call to get session duration if session is already in cache
* feat(backend): used pg pool everywhere except db service
* fix(backend): added missing part after rebase
* fix(backend): removed old sessions file
* feat(backend): added refactored redis client with produce/consume options
* feat(backend): added cache layer for projects
* fix(backend): added missing redis config
* fix(backend): added missing method for producer
* feat(backend): cache integration for sessions
* feat(backend): temporary method to get session directly from db
* feat(backend): adapt EE version of message handler
* fix(backend): fixed issue in fts realisation
* fix(backend): added redis cache to sessions module
* fix(backend): set 0 duration or hesitation time for inputs without focus event
* feat(backend): added cache for session updates and failover mechanism for batch.Insert() operation
* feat(backend): debug log
* feat(backend): more debug log
* feat(backend): removed debug log
* fix(backend): fixed an issue of tracking input events with empty label
* fix(backend): disabled debug log in projects cache
* fix(backend): renamed session updater
* fix(backend): fixed closed pool issue in DB service
* fix(backend): fixed dead lock in db Stop() method
* fix(backend): fixed panic in heuristics service
* feat(backend): enabled redis cache in projects
* feat(backend): clear cache on each update operation
* feat(backend): fully integrated cache layer with auto switch
* feat(backend): small refactoring in session updates
* fix(backend): fixed wrong events counter issue
* feat(backend): enabled full cache support in ender and http services
* fix(backend/ee): added missed import
* feat(backend): added second cache layer for db to speed up the service
* feat(backend): disable redis cache
* feat(backend): moved redis cache to ee
