#222 Removing `@Secured` from the `ExtensionManager`
#222 Moved the `AuthorizationUtils` interface to the `core` module
#222 Removing `@Secured` from the `GitService`
#222 Replacing `AuthorizationUtils.checkGlobal` by the use of the `@GlobalGrant` annotation.
#222 Replacing `AuthorizationUtils.checkProject` by the use of the `@ProjectGrant` annotation.