Engine: extended dialog options customization

This extends the possibilities for custom dialog option design for the new game versions:
* implicit option selection is disabled; the dialog option is no longer automatically run when player clicks mouse;
* "dialog_options_get_active" callback is run even if the mouse is beyond UI bounds;
* "dialog_options_mouse_click" callback is run regardless of whether mouse was over particular option or not;
* options UI no longer unconditionally redrawn if the mouse button was pressed.
Script API: implemented DialogOptionsRenderingInfo.RunActiveOption()