Manage how the HTTP API is run

[sr-gi]

Once #187 is merged, the HTTP API will be handled by gunicorn instead of using the non-production-ready flask webserver.

This is an improvements over the previous approach, but may not be good for all cases. We should give a bit of flexibility about how a user wants to run this.

Add some config options that allow users to choose how they would like to run this.

Check https://github.com/talaia-labs/python-teos/pull/187#issuecomment-668697966 and https://github.com/talaia-labs/python-teos/pull/187#pullrequestreview-461452113