feat(medcat-service): Add Gunicorn CLI args for max requests, jitter, and any other input from env

[alhendrickson]

New behaviour

• Support the two gunicorn args from this PR Ported from CU-869ah00vt Fix memory leak (mc-service) #141
• Support any other gunicorn args with an env var
• Print the whole command Gunicorn will run with to console

Usage

Given this env var in the yaml

    environment:
      - SERVER_GUNICORN_EXTRA_ARGS=--worker-connections 1 --backlog 5

See this log line

cogstack-medcat-service-production  | Starting up the service using gunicorn server ...
cogstack-medcat-service-production  | + exec gunicorn --bind 0.0.0.0:5000 --workers=1 --threads=1 --timeout=300 '--access-logformat=%(t)s [ACCESS] %(h)s "%(r)s" %(s)s "%(f)s" "%(a)s"' --access-logfile=- --error-logfile=- --log-level info --config /cat/config.py --max-requests=1000 --max-requests-jitter=50 --worker-connections 1 --backlog 5 --worker-class uvicorn.workers.UvicornWorker medcat_service.main:app
cogstack-medcat-service-production  | [2025-10-29 09:22:43 +0000] [1] [INFO] Starting gunicorn 23.0.0

[mart-r]

Looks good to me!
Getting this in without #141 makes everything else simpler!