Add support for lists of shader hashes in fossilize-prune

[R1chterScale]

I've used fossilize-prune a tiny bit and have continued to run into the relatively minor annoyance that when intending to prune to a list of shader hashes, the CLI currently requires re-specifying the filter argument for each hash, for example:

fossilize-prune --input-db Input.foz --output-db Output.foz --filter-graphics f2cb331235a3e518 --filter-graphics 0aeb4faec8c8575c ...

This can become incredibly unwieldy when attempting to prune beyond a very small number of shaders, would it be reasonable to see the CLI support listing hashes together, such as having a space or comma separating each hash?

I fully understand this is likely not to be a high priority at all, just has run into it enough to report it.