Support autocompletion of vars when including roles that contain meta/argument_specs.yml

[komish]

Problem

I don't see autocompletion provided when writing a playbook that includes a role that provides meta/argument_specs.yaml. The argument_specs.yaml provides validation at runtime, but I'd like to see completion for it as well.

Solution

The playbook that includes the role and has vars defined for it should have autocompletion provided by the language server for the included role's vars, assuming the role has provided the spec. This is similar behavior to what we see for module vars.

Alternatives

No response

Additional context

#606 was opened/closed and appears to have the same ask. That issue specifies that this is already supported, but I think (a) there was a miscommunication in what was desired, or (b) there needs to be better documentation about how to use this feature if it's already implemented.

I will note that including meta/argument_specs.yaml does seem to automatically trigger argument_spec_validation, which is great, but I'd like users who pull in the role to have some autocompletion when they're calling it.

[alisonlhart]

This is a good feature suggestion and we have this on our roadmap. This feature is what I understood #1764 to be, but your issue here is what is planned for the future. Thank you for raising that clarification!