* add get mute timing by name to MuteTimingService
* update get mute timing request handler to use the service method
* replace validation, uniqueness and used errors with errutils
* update mute timing methods return errutil responses
* use the term "time interval" in errors bevause mute timings are deprecated in Alertmanager and will be replaced by time intervals in the future.
* update create and update methods to return struct instead of pointer
* Generate API for writing templates
* Persist templates app logic layer
* Validate templates
* Extract logic, make set and delete methods
* Drop post route for templates
* Fix response details, wire up remainder of API
* Authorize routes
* Mirror some existing tests on new APIs
* Generate mock for prov store
* Wire up prov store mock, add tests using it
* Cover cases for both storage paths
* Add happy path tests and fix bugs if file contains no template section
* Normalize template content with define statement
* Tests for deletion
* Fix linter error
* Move provenance field to DTO
* empty commit
* ID to name
* Fix in auth too
