MM-12843 Add interactive dialogs (#9816)

* Add interactive dialogs

* Fix unit test

* Updates per feedback

* Fix typo

* Updates per feedback, add icon_url and error returns

* Updates per feedback

* Update per feedback

model/command_response.go

@@ -25,6 +25,7 @@ type CommandResponse struct {
 	Type           string             `json:"type"`
 	Props          StringInterface    `json:"props"`
 	GotoLocation   string             `json:"goto_location"`
+	TriggerId      string             `json:"trigger_id"`
 	Attachments    []*SlackAttachment `json:"attachments"`
 	ExtraResponses []*CommandResponse `json:"extra_responses"`
 }