fix: #19527 - add ariaLabel input to breadcrumb component for accessi…

[vitopio-prete]

Fixes #19527

Description

The p-breadcrumb component's root <nav> element had no accessible label, causing axe-core landmark-unique violations when multiple breadcrumb instances appear on the same page.

Although the documentation states that aria-label can be passed implicitly to the root, this is not currently the case, the attribute is not forwarded to the inner <nav>, so consumers have no way to set it without DOM manipulation.

Changes

• Added an ariaLabel input (string | undefined) on p-breadcrumb, following the same pattern already used in other navigation components such as p-menu
• Bound [attr.aria-label]="ariaLabel" on the root <nav> element
• Updated the component's API documentation
• Added unit tests covering both the DOM attribute binding and the undefined default behavior

Usage

<!-- Single breadcrumb -->
<p-breadcrumb [model]="items" ariaLabel="Breadcrumb" />

<!-- Multiple breadcrumbs on the same page -->
<p-breadcrumb [model]="items1" ariaLabel="Primary navigation" />
<p-breadcrumb [model]="items2" ariaLabel="Secondary navigation" />

Notes

• Default value is undefined to preserve current behavior and avoid unexpected changes for existing consumers. Consumers are expected to provide a meaningful label when needed (following the W3C APG breadcrumb pattern).
• No breaking changes.