* Nested Folders: Support getting of nested folder in folder service when feature flag is set
* Fix lint
* Fix some tests
* Fix ngalert test
* ngalert fix
* Fix API tests
* Fix some tests and lint
* Fix lint 2
* Fix library elements and panels
* Add access control to get folder
* Cleanup and minor test change
* make 'for' pointer to distinguish between missing field and 0
* set 'for' to -1 if the value is missing but not allow negative in the request + path -1 with the value from original rule
* update store validation to not allow negative 'for'
* update usages to use pointer
* Update API controller
- add validation of rules API model
- add function to calculate changes between the submitted alerts and existing alerts
- update RoutePostNameRulesConfig to validate input models, calculate changes and apply in a transaction
* Update DBStore
- delete unused storage method. All the logic is moved upstream.
- upsert to not modify fields of new by values from the existing alert
- if rule has UID do not try to pull it from db. (it is done upstream)
* Add rule generator