disable instrumentation and notification for readonly commands

[creamsoup]

motivation:
view, json, status, analyze_logs commands errored out (prometheus port already used) when I have Prometheus manager.py running.

suggested fix:
readonly commands ignores notification and instrumentation config values

$ python manager.py json
Traceback (most recent call last):
  File "/home/creamsoup/git/Swar-Chia-Plot-Manager/manager.py", line 39, in <module>
    json_output()
  File "/home/creamsoup/git/Swar-Chia-Plot-Manager/plotmanager/library/utilities/commands.py", line 109, in json_output
    jobs, running_work = get_running_plots(jobs=jobs, running_work=running_work,
  File "/home/creamsoup/git/Swar-Chia-Plot-Manager/plotmanager/library/utilities/processes.py", line 254, in get_running_plots
    set_plots_running(total_running_plots=assumed_job.total_running, job_name=assumed_job.name,
  File "/home/creamsoup/git/Swar-Chia-Plot-Manager/plotmanager/library/utilities/instrumentation.py", line 24, in set_plots_running
    _get_metrics(instrumentation_settings=instrumentation_settings)
  File "/home/creamsoup/git/Swar-Chia-Plot-Manager/plotmanager/library/utilities/instrumentation.py", line 19, in _get_metrics
    start_http_server(port)
  File "/home/creamsoup/git/Swar-Chia-Plot-Manager/venv/lib/python3.9/site-packages/prometheus_client/exposition.py", line 149, in start_wsgi_server
    httpd = make_server(addr, port, app, ThreadingWSGIServer, handler_class=_SilentHandler)
  File "/usr/lib/python3.9/wsgiref/simple_server.py", line 154, in make_server
    server = server_class((host, port), handler_class)
  File "/usr/lib/python3.9/socketserver.py", line 452, in __init__
    self.server_bind()
  File "/usr/lib/python3.9/wsgiref/simple_server.py", line 50, in server_bind
    HTTPServer.server_bind(self)
  File "/usr/lib/python3.9/http/server.py", line 138, in server_bind
    socketserver.TCPServer.server_bind(self)
  File "/usr/lib/python3.9/socketserver.py", line 466, in server_bind
    self.socket.bind(self.server_address)
OSError: [Errno 98] Address already in use