Allow completing slash command arguments from extensions (#13240)

This PR extends the extension API with support for completing slash
command arguments for slash commands defined in extensions.

Release Notes:

- N/A

Marshall Bowers committed 2y ago

db0d843fb15e858b31094dd324d2e5771a364d51

Parent: ad4e528

Committed by GitHub <noreply@github.com> on 6/18/2024, 9:58:57 PM