Add autocomplete for date element to be a11y compliant

Attached is the patch that turns autocomplete on.
Didn't add it to the dataBase file, because dateList should not get autocomplete attributes.

Can confirm it works as advertised. This was my testing process:

• Apply patch
• Enable Webform UI
• Add "Birth Date" date field to contact form
• Scroll down to "Form Display" section, see Autocomplete option defaulted to "On"
• Save form
• View form
• Begin typing name in Name field, use autocomplete to fill out the field
• Verify that Email and Birth Date fields are also autocompleted

Please use an issue fork and merge request.

Working on it!!

Created an MR for this issue!!
Please review!!