[feature:] use `stockplotr::convert_output()` for all models

[kellijohnson-NOAA]

Describe the situation that led to the request and a solution

I would like to use asar::convert_output() to read the model files to compare them with FIMS. This came about because we are wanting to be able to compare SPR reference points once we have them in FIMS. So @KyleShertzer-NOAA and I were going to look at each legacy model to see where we could find them and it dawned on me 🤯 that we could just switch to {asar} formats and get all of the information in a standardized way to be able to compare multiple models 🥇.

Checkbox	Stock	Status

• NEFSC yellowtail flounder | not sure if ASAP is supported
• AFSC GOA pollock | no converter available
• SWFSC sardine | SS3 should work
• NWFSC petrale | SS3 should work
• PIFSC opakapaka | SS3 should work
• SEFSC scamp | tried it but need to write code
• hake | Bayesian so maybe just compare MLE

Alternative solutions

Find the information that we need from each assessment platform. Or, create our own functions to do this. Neither are ideal.

Statistical validity

No response

Additional context

No response