Allow modals to override their dismissal

Co-Authored-By: Mikayla Maki <mikayla.c.maki@gmail.com>

crates/collab_ui2/src/collab_panel/channel_modal.rs

@@ -13,6 +13,7 @@ use picker::{Picker, PickerDelegate};
 use std::sync::Arc;
 use ui::prelude::*;
 use util::TryFutureExt;
+use workspace::ModalView;
 
 actions!(
     SelectNextControl,
@@ -140,6 +141,7 @@ impl ChannelModal {
 }
 
 impl EventEmitter<DismissEvent> for ChannelModal {}
+impl ModalView for ChannelModal {}
 
 impl FocusableView for ChannelModal {
     fn focus_handle(&self, cx: &AppContext) -> gpui::FocusHandle {