Add jq stage to fud2

[rachitnigam]

Adding jq stage to fud2 but I've been having trouble getting the stage to print out the value from the command. It seems like the jq ... > $out call gobbles up the output. Not sure if I'm making a mistake.

Any thoughts @EclecticGriffin @ekiwi or @sampsyo?

[EclecticGriffin]

Seems to be working for me? I was able to run

 fud2 --from calyx --to jq --through cider -s sim.data=benchmarks/ntt-32.futil.data -s calyx.args="--log off" benchmarks/ntt-32.futil -s jq.expr="." -s jq.flags="--sort-keys"

and got mostly the expected result, minus a missing newline at the very end.

Feels like we could use jq.expr as "." by default but don't think that's strictly required

[rachitnigam]

Huh, I don't seem to get any output when using it for some reason but if you say it works, I'll transition the tests to use it!

[EclecticGriffin]

Looks good to me, assuming CI is happy!