allow wildcard files to have comment lines

[rubberbaron]

This PR allows very simple comments in Wildcards files: if lines start with "#", they are a comment.

Having comments allows wildcard files shared between people to contain authorship information, sources, and other information.

Beyond wanting this on general principle, I personally want it for compatibility:

I'll be releasing my extended wildcards extension at some point, and it will include a number of built-in public domain wildcard lists. Because my library supports comments, I have information in them like:

# cc0. derived from https://github.com/dariusk/corpora
# validated in SD 1.5 with "a __animal__"
# excluded due to issues: gnu, musk, mustang, mole, newt, puma, silver fox, wolverine
aardvark
alligator
alpaca
antelope
ape
[etc.]

However, I intentionally don't use any other features not found in this Wildcards library other than these comments, so this small change will make those files compatible.

[rubberbaron]

I verified that this is the basic comment format used by Dynamic Prompts as well. (Like my extension, it supports more general comments everywhere, but I think this PR represents a reasonable compromise between making the Wildcards extension more compatible without introducing too much extra complexity.)