File upload component issues

[danielelder]

The govFileUpload component contains the following issues:

• Hard coded "error:" prefix does not allow for Welsh language translation.
• It appears that a list of files uploaded is displayed after the file upload button. If this is true then the only indication that they are successful uploads is by the use of colour "slds-text-color_success".
• If the file uploading is done using Javascript and doesn't take the user to a new page then an aria-live region should be used to keep screen reader users informed of the file upload progress.