Actualize and fix code example in Creating Chart with Incremental Data Update

[lovtsovaik]

Environment

• Documentation version: 7.2
• Part of the documentation: Charts
• Existing page: https://doc.cuba-platform.com/charts-7.2/charts.html#section_incremental_data_update

Description of the bug or enhancement

§2.6.5

1. Actualize steps in point 4 according to the new version of the platform
   Designer tab -> Component Palette (?)
   Non-visual components -> Fasets

2. The onTimer field is deprecated, needs to subscribe to TimerActionEvent in the screen controller instead (see https://doc.cuba-platform.com/manual-7.2/gui_Timer.html)
   So the example needs to be updated

3. Typo in code: ;; in updateChart function (in point 5 and 6)

4. Not working functionality:

When the queue size exceeds 10 items, the oldest item is excluded.

add itemsQueue.add(initialValue); after ordersDc.getMutableItems().add(initialValue);
and replace ordersDc.getMutableItems().add(item); on ordersDc.getMutableItems().remove(item);