Reconsider CLI design

[frewsxcv]

i haven't thought too hard about this, but i think the CLI could be improved. for example, it's unclear to me when i have a certain experiment if it's already been run, what toolchain it used, etc. another painpoint is if i specify define-ex nightly beta, and it's been a few days, i'm unsure which exact nightly the experiment ran on

toolchains (are these necessary?):

cargobomb toolchain --list
cargobomb toolchain --add nightly

experiments:

cargobomb experiment new --type comparison <toolchain1> <toolchain2>
cargobomb experiment new --type query <toolchain>
cargobomb experiment prepare
cargobomb experiment run
cargobomb experiment gen-report

i'll probably update this more as i'll probably have further thoughts about this. curious if anyone else has opinions

[tomprince]

I was looking into this, and the only commands that wouldn't fall under cargobomb experiment are prepare-local and create-lists.

[tomprince]

(Given the restricted command list exposed in #24).