Fix: Correct focus order in panel header for accessibility.

[ZallaxDev]

The standard panel component's header had a mismatch between the visual order of controls and the keyboard focus order on mobile/tablet views, violating WCAG 2.4.3 (Focus Order).

This was caused by CSS Flexbox order properties that visually re-arranged the actions and sortation controls on smaller screens without changing their underlying DOM order, creating a confusing and illogical navigation path for keyboard and screen reader users.

Changes:

• Modified _ui-component_panel.scss to align the flex order with the DOM order for .panel-viewcontrols and .panel-controls across all breakpoints.
• This ensures the tabbing sequence is consistent with the visual layout, providing a predictable user experience.
• The visual order on mobile now follows the DOM, presenting the sortation control before the actions dropdown.

Ticket 41479