Add pagination for dashboard and user activity feeds (#22937)

Previously only the last few activities where available. This works for
all activity and for activity on a date chosen on the heatmap.

models/activities/action.go

@@ -380,14 +380,14 @@ type GetFeedsOptions struct {
 }
 
 // GetFeeds returns actions according to the provided options
-func GetFeeds(ctx context.Context, opts GetFeedsOptions) (ActionList, error) {
+func GetFeeds(ctx context.Context, opts GetFeedsOptions) (ActionList, int64, error) {
 	if opts.RequestedUser == nil && opts.RequestedTeam == nil && opts.RequestedRepo == nil {
-		return nil, fmt.Errorf("need at least one of these filters: RequestedUser, RequestedTeam, RequestedRepo")
+		return nil, 0, fmt.Errorf("need at least one of these filters: RequestedUser, RequestedTeam, RequestedRepo")
 	}
 
 	cond, err := activityQueryCondition(opts)
 	if err != nil {
-		return nil, err
+		return nil, 0, err
 	}
 
 	sess := db.GetEngine(ctx).Where(cond).
@@ -398,16 +398,16 @@ func GetFeeds(ctx context.Context, opts GetFeedsOptions) (ActionList, error) {
 	sess = db.SetSessionPagination(sess, &opts)
 
 	actions := make([]*Action, 0, opts.PageSize)
-
-	if err := sess.Desc("`action`.created_unix").Find(&actions); err != nil {
-		return nil, fmt.Errorf("Find: %w", err)
+	count, err := sess.Desc("`action`.created_unix").FindAndCount(&actions)
+	if err != nil {
+		return nil, 0, fmt.Errorf("FindAndCount: %w", err)
 	}
 
 	if err := ActionList(actions).loadAttributes(ctx); err != nil {
-		return nil, fmt.Errorf("LoadAttributes: %w", err)
+		return nil, 0, fmt.Errorf("LoadAttributes: %w", err)
 	}
 
-	return actions, nil
+	return actions, count, nil
 }
 
 // ActivityReadable return whether doer can read activities of user