https://ctan.org/ can help looking up packages and it seems that it also finds
files but I could be wrong.

As far as I know, MikTeX (on Windows...) can automatically download a missing
package when a compilation fails.
I don't know if TeXlive can do this and if not, it might be a lot of work to get
this change accepted upstream...

-- 
Pierre Neidhardt
https://ambrevar.xyz/