Passing multiple --theoryCorrs and --pdfs isn't supported

[lucalavezzo]

Running the histmaker with different theory corrections corresponding to different pdfs, and different --pdfs, isn't supported.
Likely, there is an assumption when applying the event weights that the theory corrections are always wrt to the first one, or the first pdf, or something like this.

We should either add this support, or not allow people to pass these options.

This ties in to the discussion we had to clean up theory corrections, including via a centralized dataclass.

[davidwalter2]

This issue is damned