Replace min and max with ge, gt, le and lt
Update and fix params/values of numeric CLI argparser arguments
Rewrite num() tests

This rewrite is required for being able to add numeric CLI args which allow a min value of 0. This is currently not possible, as num() is checking for value >= min. Min values of int args were set to -1 because of this, but this doesn't work for float args (there currently are none of that kind, but I'm intending to add one).

--player-external-http-port had an incorrect min value, as the default is set to 0
--stream-segment-threads is now properly clamped between 1 and 10
all int args have their min value set via ge instead of gt