Cull weak lines from VALD linelists

[jvshields]

Currently, VALD linelists can include thousands to tens of thousands of lines that may effectively not contribute to a stellar spectrum computed by STARDIS. I believe parsers and subsequent handling of other sources has some functionality to handle situations like this, and it would be good to include in our VALD handling.

[manas-dhyani]

Hi @jvshields,

I'm working on implementing the culling of weak lines from VALD linelists for issue #415. Would you recommend specific thresholds for log_gf or e_low, or should they be based on existing filtering criteria used in other linelists?

Currently, I’m considering using log_gf > -5 and e_low > 0.1 eV, but I’d like to confirm whether these values are appropriate.Looking forward to your guidance!