TAP: Modify the xSV formats in order to let developer specify a MIME type and short MIME type (or alias) for any SV format, but especially for the one not already managed (CSV and TSV).

Revert "TAP: Modify the xSV formats in order to let developer specify a MIME type and short MIME type (or alias) for any SV format, but especially for the one not already managed (CSV and TSV)."

This reverts commit 2379c606.

TAP: Modify the xSV formats in order to let developer specify a MIME type and short MIME type (or alias) for any SV format, but especially for the one not already managed (CSV and TSV).