VEDUHSF Fixes -Re-encode uploaded TXT files whose content is not valid UTF-8/ANSI

[freeheeling]

Follow-on work from Document Supporting Documentation File Upload Validations #75347 investigation

A validation failure that happens to occur with great frequency is invalid file text encoding. It merits verifying whether or not uploaded TXT files are UTF-8/ANSI encoded as part of the validation process, given that these encompass the majority of error response types returned by EVSS. Some options to address this encoding issue are mentioned here. It may be necessary to re-encode uploaded TXT files if their content is not valid UTF-8/ANSI, before storing them to S3.

[ajones446]

Update from August 20 meeting: we decided not to re-encode uploaded TXT files if their content is not valid. We should try to validate encoding before storing to S3 and display an error message before the user submits the form.