Upgrade the "testmode" pipeline script to just pipeline script

[SamuelBrand1]

At the moment, the "testmode" script https://github.com/CDCgov/Rt-without-renewal/blob/main/pipeline/scripts/run_testmode_pipeline.jl is very close to the actual pipeline script. I think it just needs renamed, but maybe we want some more functionality?

At the moment, you use from the command line as:

julia path\to\script ndraws

and it will sample ndraws for each scenario in each pipeline.