[feature] Add paging via Link header for notifications and account statuses (#629)

* test link headers

* page get account statuses properly

* page get notifications

* add util func for packaging timeline responses

* return timelined stuff from accountstatusesget

* rename timeline response

* use new convenience function

* go fmt

internal/api/model/notification.go

@@ -43,3 +43,24 @@ type Notification struct {
 	// Status that was the object of the notification, e.g. in mentions, reblogs, favourites, or polls.
 	Status *Status `json:"status,omitempty"`
 }
+
+/*
+	The below functions are added onto the apimodel notification so that it satisfies
+	the Timelineable interface in internal/timeline.
+*/
+
+func (n *Notification) GetID() string {
+	return n.ID
+}
+
+func (n *Notification) GetAccountID() string {
+	return ""
+}
+
+func (n *Notification) GetBoostOfID() string {
+	return ""
+}
+
+func (n *Notification) GetBoostOfAccountID() string {
+	return ""
+}