chore(ui5-toolbar): toolbar item wrapper introduced

[PetyaMarkovaBogdanova]

feat(ui5-toolbar-item): Refactor to a physical item for enhanced overflow logic

The ui5-toolbar-item has been refactored from an abstract item to a physical item, enabling the transfer of logic for overflowPriority and preventOverflowClosing directly to it.

Key Enhancements:

• Universal Wrapping: The ui5-toolbar-item can now wrap all types of components, allowing them to participate in the overflow toolbar logic seamlessly.
• Pre-defined Wrappers: For certain components, pre-defined wrappers are available. A console warning is displayed to encourage their use when applicable.
• 100% Expansion in Overflow: Components that need to expand fully in the overflow popover can now implement the expandInOverflow property.
• Self Overflow Logic: Components with internal overflow logic can implement the selfOverflowed property.

This enhancement improves flexibility and ensures better integration of components within the overflow toolbar logic.

[ui5-webcomponents-bot]

🧹 Preview deployment cleaned up: https://pr-12243--ui5-webcomponents.netlify.app

[dobrinyonkov]

General comment - the new component ToolbarItem does not appear in the website playground. Perhaps it needs a directory in the website package. We should then check if all APIs are correctly documented.