ui5-textarea: [a11y] provide aria-label or aria-labelledby property in ui5-textarea

[zhangliangyi]

Dear colleague,

I am from Successfactors Web Experience Shanghai team.

Describe the bug As the id defined in for property of ui5-label takes no effect to the inner input element in shadow DOM, the aria-label or aria-labelledby property is required for screen reader to identify the linked label.

But so far neither aria-label nor aria-labelledby is exposed from the component.

To reproduce Steps to reproduce the behavior:

1. Go to https://sap.github.io/ui5-webcomponents/playground/components/Label/
2. Go to section Label 'for'
3. Focus to the ui5-textarea and check the output of screen reader.

Expected behavior When focus to the datepicker, select or textarea, the linked label should be read.

Context

• UI5 Web Components version: 0.23.0
• OS/Platform: macOS 10.15.6
• Browser (if relevant): Microsoft Edge
• Other information: Screen Reader - NVDA

Affected components (if known)

• ui5-textarea
• ui5-datepicker
• ui5-select

Thanks Jacob

[ilhan007]

Provided aria-label or aria-labelledby property for the following components: ui5-textarea, ui5-datepicker and ui5-select

https://github.com/SAP/ui5-webcomponents/pull/2126 https://github.com/SAP/ui5-webcomponents/pull/2125 https://github.com/SAP/ui5-webcomponents/pull/2124

Best, ilhan