Modify-able aria labels

[adelriosantiago]

Is your feature request related to a problem? Please describe.
The aria-label for new elements is always "Search for option" however this will trigger an accessibility issue if the developer wants a different placeholder text (for example "Pick from the list"). In this scenario the placeholder and the aria-label would not match.

Describe the solution you'd like
I would expect to be able to pass the desired label as a prop.

Additional context
Here is the screenshot of the default aria label:

And the line of this default text is here: https://github.com/sagalbot/vue-select/blob/master/src/components/Select.vue#L977

[chrisdant]

This would be great to have! Essential to having a good user experience for screen readers.