Add AsyncAPI support in the stats command #2353
Description
Is your feature request related to a problem? Please describe.
We support stats for OpenAPI 3.x only at the moment. Since we've added AsyncAPI support for lint and bundle, it makes sense to add the support to other commands.
Describe the solution you'd like
Add the support for AsyncAPI in the stats command.
As a part of this ticket, we can also implement other stats, like circular references count.
Describe alternatives you've considered
Doing nothing.
Additional context
Related: #2352.