a11y - site setup - Date and Time - cancel/delete buttons input fields - cms ui

[Wagner3UB]

Describe the bug

• None of the 'x' buttons work to cancel an item when using the keyboard. Additionally, not all of them are reachable using the keyboard.
• Along with this issue, it's necessary to pay attention to other accessibility points, such as set the correct labels.

To Reproduce
Steps to reproduce the behavior:

1. Go to "site setup" -> "Date and Time"
2. With a screen reader + keyboard, go to any input and try to add and delete the items

→ to access the "Available timezones" item and the close button for a single item:

1. go inside the input
2. with one or more items previously set, press the "arrow left" on the keyboard. This button doesn't work with the keyboard.

→ the small red button on the right (clear field), inside all the inputs, it is not reachable by keyboard

Expected behavior

• The item close button must delete the selection of the current item.
• The small red button on the right needs to work exclusively for 'Available timezones'. It does not serve a proper purpose for the first and third input. Those are required fields.

Screenshots
If applic

Software (please complete the following information):

Volto Version 17.0.0-alpha.19
Plone Version 6.0.4