feat(ui5-timeline-item): introduce status property

[hinzzx]

Introducing status property into the <ui5-timeline-item> web component.

The status property allows you to set the semantic state of the icon using the following values: Information, Positive, Critical, Negative or None.
Each status automatically changes the icon's color to visually represent the corresponding state, improving clarity and consistency.
The status is also accessible. Screen readers will read the status, ensuring that users with assistive technologies can understand the semantic meaning.

Sample usecases with and without status property

With

Without

[unazko]

• From the commit description - the semantic meaning gets set over the ui5-timeline-item and not only over the icon.
• You could add a test, in order to check whether the accessible-description property results into aria-description over the inner element.

Tested with NVDA and JAWS. The announcements are as expected.