Match a single line inside of an apt sources.list file and return content in named groups.

This regex should take into account many possible variations of a sources.list entry, but by far not all of them.

What it does:

• recognize most of the protocols supported by apt
• require the URI to begin with a domain of a remote machine, when using those protocols, which require this
• support for optional arguments like options and arbitrarily many components
• case sensitivity for the possibility of the suite containing an exact path, in which case the line mustn't contain any components

That it does not:

• support spaces inside the URI, which APT also doesn't as far , as I know
• support uncommon characters in URI and components
• usage of IP addresses instead of domains
• split list of options or components into separate groups
• validity check for options