* AccessControl: Implement a way to register fixed roles
* Add context to register func
* Use FixedRoleGrantsMap instead of FixedRoleGrants
* Removed FixedRoles map to sync.map
* Wrote test for accesscontrol and provisioning
* Use mutexes+map instead of sync maps
* Create a sync map struct out of a Map and a Mutex
* Create a sync map struct for grants as well
* Validate builtin roles
* Make validation public to access control
* Handle errors consistently with what seeder does
* Keep errors consistant amongst accesscontrol impl
* Handle registration error
* Reverse the registration direction thanks to a RoleRegistrant interface
* Removed sync map in favor for simple maps since registration now happens during init
* Work on the Registrant interface
* Remove the Register Role from the interface to have services returning their registrations instead
* Adding context to RegisterRegistrantsRoles and update descriptions
* little bit of cosmetics
* Making sure provisioning is ran after role registration
* test for role registration
* Change the accesscontrol interface to use a variadic
* check if accesscontrol is enabled
* Add a new test for RegisterFixedRoles and fix assign which was buggy
* Moved RegistrationList def to roles.go
* Change provisioning role's description
* Better comment on RegisterFixedRoles
* Correct comment on ValidateFixedRole
* Simplify helper func to removeRoleHelper
* Add log to saveFixedRole and assignFixedRole
Co-authored-by: Vardan Torosyan <vardants@gmail.com>
Co-authored-by: Jeremy Price <Jeremy.price@grafana.com>
