Allow several verbs with same name and different invocation patterns

Use case: allow both :e (using the current selected file and line) and :e new/file.txt allowing creation. This would allow merging the current :edit and :create verbs.

If you have other use cases, please tell me.

Original discussion: https://miaou.dystroy.org/3?Code_Croissants#15597052 (in French)

There are some concerns due to ergonomics.

For example it makes it impossible to have useful hints on how to complete the command.

So I'm not sure I'll implement this.