Password policy (#82268)

* add password service interface

* add password service implementation

* add tests for password service

* add password service wiring

* add feature toggle

* Rework from service interface to static function

* Replace previous password validations

* Add codeowners to password service

* add error logs

* update config files


---------

Co-authored-by: Karl Persson <kalle.persson@grafana.com>

pkg/api/org_invite.go

@@ -270,6 +270,10 @@ func (hs *HTTPServer) CompleteInvite(c *contextmodel.ReqContext) response.Respon
 		}
 	}
 
+	if err := completeInvite.Password.Validate(hs.Cfg); err != nil {
+		return response.Err(err)
+	}
+
 	cmd := user.CreateUserCommand{
 		Email:        completeInvite.Email,
 		Name:         completeInvite.Name,