Fix wrong download urls with shared repos

[cibere]

This PR fixes #459 using the potential solution I mentioned there.

Quick Overview

Instead of fetching the first release artifact, check the amount of assets, and if there are more than 1, attempt to find one with the same name as the current download url. If there is only 1 asset, or no asset with the same filename could be found, then default to the first asset.

This would leave the current behavior for plugins that have their own repository, but for plugins that share a repository, would require the plugin dev to ensure the proper artifact names correspond to the correct plugin.

When it comes to getting the original filename, I decided to use a regex:

https://github\.com/(?P<author>[a-zA-Z0-9-]+)/(?P<repo>[a-zA-Z0-9\.\-\_]*)/releases/download/(?P<version>[a-zA-Z\.0-9]+)/(?P<filename>.*)\.zip

which I've tested against the current set of plugins, and made it fit the username/repo name requirements that I could find.

If you want me to move away from the regex, to something like this:

filename = info[url_download].split("/")[-1]

then lmk.

I also went ahead and fixed the urls in the Search Unicode - Identify and Search Unicode - Search plugins so that another PR isn't needed to do that

[cibere]

Not exactly sure why the link checker workflow is failing. It says a configuration error, but it only seems to fail on this PR