Check spws up front

[steven-murray]

Just checks that input spw's to the pspec_run function are valid, before reading too much stuff in, and print out helpful info if it fails.

[steven-murray]

@adeliegorce that was my first thought as well, and maybe that's the right thing to do (I don't know hera_pspec well). However, I changed my mind and put it in pspec_run because if it's in pspec it's already done a bunch of stuff and taken a while before you know that things are wrong. It turns out to be easy to get the spws wrong from makeflow because you previously select other spws that can conflict with the pspec ones.

[codecov[bot]]

Codecov Report

Base: 95.98% // Head: 95.98% // No change to project coverage :thumbsup:

Coverage data is based on head (dcba4d4) compared to base (dcba4d4). Patch has no changes to coverable lines.

:exclamation: Current head dcba4d4 differs from pull request most recent head 468261d. Consider uploading reports for the commit 468261d to get more accurate results

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[adeliegorce]

Okay, makes sense!