Add @log_route decorator
Add @log_route decorator

This decorator can be added to routes. It binds data to the logger that
is shown with all log messages created during the response.

- binds the method and path to the logger
- binds a unique identifier to the log messages for a given response.
- measure the time duration of the response
- generates a final log message for the route with the time duration.

lsst-sqre/ltd-keeper,lsst-sqre/ltd-keeper