* Chore: remove session storage references

* Small refactoring of the settings module

* Update docs - remove references for the session storage

* Update config files (sample and default configs)

* Add tests for warning during the config load on defined storage cache

* Remove all references to session storage

* Remove macaron session dependency

* Remove leftovers

* Fix: address review comments

* Fix: remove old deps

* Fix: add skipStaticRootValidation = true to tests

* Fix: improve the docs and warning message

As per discussion in here - https://github.com/grafana/grafana/pull/16445/files#r273026255

* Chore: make linter happy

Fixes #16148
Ref #16114