The URLS file is no longer necessary as urls are now generated directly from the app VHOST file.
This also moves all the url generation logic to the domains plugin.
GLOBAL_VHOST_PATH and GLOBAL_VHOST_FILE were used to represent the same
thing. Same for APP_URLS_PATH and APP_VHOST_PATH.
This normalizes all of those to _PATH.
This standardization makes it somewhat easier to read stacktraces as the command names are all uniform, so it will be slightly easier to scan trace output.
If the subdomain is url-like, assume it is a valid url and use it for the default domain name. This allows users to specify the default domain for an app even if that is a subdomain of a global vhost.
Closes#3529
The `domains` command previously had this functionality, but is deprecated, and thus we should provide an alternative method of presenting the information.
While I do not agree with _every_ style change, this will force Dokku to have consistent formatting across all shell scripts, which is arguably a Good Thing™.
The command used to reprocess everything is:
```shell
shfmt -l -bn -ci -i 2 -w .
```
This allows users to quickly show the state of any configured application, as well as the state of their server. In doing so, we make it easy for them to provide information necessary for debugging in a single command.
